View VCA2612_9084652.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

dual, variable gain amplifier with low noise preamp features low noise preamp: ? low input noise: 1.25nv/ hz ? active termination noise reduction ? switchable termination value ? 80mhz bandwidth ? 5db to 25db gain range ? differential input /output low noise variable gain amplifier: ? low noise vca: 3.3nv/ hz, differential programming optimizes noise figure ? 24db to 45db gain ? 40mhz bandwidth ? differential input /output low crosstalk: 52db at max gain, 5mhz high-speed variable gain adjust switchable external processing applications ultrasound systems wireless receivers test equipment VCA2612 VCA2612 description the VCA2612 is a highly integrated, dual receive channel, signal processing subsystem. each channel of the product consists of a low noise preamplifier (lnp) and a variable gain amplifier (vga). the lnp circuit provides the neces- sary connections to implement active termination (at), a method of cable termination which results in up to 4.6db noise figure improvement. different cable termination char- acteristics can be accommodated by utilizing the VCA2612s switchable lna feedback pins. the lnp has the ability to accept both differential and single-ended inputs, and gener- ates a differential output signal. the lnp provides strappable gains of 5db, 17db, 22db, and 25db. the output of the lnp can be accessed externally for further signal processing, or fed directly into the vga. the VCA2612s vga section consists of two parts: the voltage controlled attenuator (vca) and the programmable gain amplifier (pga). the gain and gain range of the pga can be digitally programmed. the combination of these two programmable elements results in a variable gain ranging from 0db up to a maximum gain as defined by the user through external connections. the output of the vga can be used in either a single-ended or differential mode to drive high-performance analog-to-digital (a/d) converters. the VCA2612 also features low crosstalk and outstanding distortion performance. the combination of low noise and gain range programmability make the VCA2612 a versatile building block in a number of applications where noise performance is critical. the VCA2612 is available in a tqfp-48 package. low noise preamp 5db to 25db programmable gain amplifier 24 to 45db voltage controlled attenuator analog control maximum gain select rf 2 rf 1 fb swfb lnp in p c c c f lnp in n lnp gs1 lnp gs2 lnp gs3 lnp gain set input lnp out p sel vca in p lnp out nvca in nvca cntl fbsw cntl vca out p vca out n mgs 1 mgs 2 mgs 3 maximum gain select VCA2612 (1 of 2 channels) www.ti.com copyright ? 2000-2004, texas instruments incorporated please be aware that an important notice concerning availability, standard warranty, and use in critical applications of texas instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. sbos117c C september 2000 C revised april 2004 production data information is current as of publication date. products conform to specifications per the terms of texas instruments standard warranty. production processing does not necessarily include testing of all parameters. all trademarks are the property of their respective owners.
VCA2612 2 sbos117c www.ti.com electrical characteristics at t a = +25 c, v dda = v ddb = v ddr = +5v, load resistance = 500 ? on each output to ground, mgs = 011, lnp = 22db and f in = 5mhz, unless otherwise noted. the input to the preamp (lnp) is single-ended, and the output from the vca is single-ended unless otherwise noted. absolute maximum ratings (1) power supply (+v s ) ............................................................................. +6v analog input ............................................................. C 0.3v to (+v s + 0.3v) logic input ............................................................... C 0.3v to (+v s + 0.3v) case temperature ......................................................................... +100 c junction temperature .................................................................... +150 c storage temperature ...................................................... C 40 c to +150 c note: (1) stresses above these ratings may cause permanent damage. exposure to absolute maximum conditions for extended periods may degrade device reliability. package package ordering transport product package-lead designator marking number media, quantity VCA2612y tqfp-48 pfb VCA2612y VCA2612y/250 tape and reel, 250 """" VCA2612y/2k tape and reel, 2000 package/ordering information (1) note: (1) for the most current package and ordering information, see the package option addendum located at the end of this dat a sheet. electrostatic discharge sensitivity this integrated circuit can be damaged by esd. texas instru- ments recommends that all integrated circuits be handled with appropriate precautions. failure to observe proper handling and installation procedures can cause damage. esd damage can range from subtle performance degradation to complete device failure. precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. VCA2612y parameter conditions min typ max units preamplifier input resistance 600 k ? input capacitance 15 pf input bias current 1na cmrr f = 1mhz, vca cntl = 0.2v 50 db maximum input voltage preamp gain = +5db 1 v pp preamp gain = +25db 112 mv pp input voltage noise (1) preamp gain = +5db 3.5 nv/ hz preamp gain = +25db 1.25 nv/ hz input current noise independent of gain 0.35 pa/ hz noise figure, r s = 75 ? , r in = 75 ? (1) r f = 550 ? , preamp gain = 22db, 6.2 db pga gain = 39db bandwidth gain = 22db 80 mhz programmable variable gain amplifier peak input voltage differential 2 v pp C 3db bandwidth 40 mhz slew rate 300 v/ s output signal range r l 500 ? each side to ground 2 v pp output impedance f = 5mhz 1 ? output short-circuit current 40 ma third harmonic distortion f = 5mhz, v out = 1v pp , vca cntl = 3.0v C 45 C 71 dbc second harmonic distortion f = 5mhz, v out = 1v pp , vca cntl = 3.0v C 45 C 63 dbc imd, two-tone v out = 2v pp , f = 1mhz C 80 dbc v out = 2v pp , f = 10mhz C 80 dbc 1db compression point f = 5mhz, output referred, differential 6 v pp crosstalk v out = 1v pp , f = 1mhz, max gain both channels 68 db group delay variation 1mhz < f < 10mhz, full gain range 2ns dc output level, v in = 0 2.5 v accuracy gain slope 10.9 db/v gain error 1 (2) db output offset voltage 50 mv total gain vca cntl = 0.2v 18 21 24 db vca cntl = 3.0v 47 50 53 db gain control interface input voltage (vca cntl ) range 0.2 to 3.0 v input resistance 1m ? response time 45db gain change, mgs = 111 0.2 s power supply operating temperature range C 40 +85 c specified operating range 4.75 5.0 5.25 v power dissipation operating, both channels 410 495 mw thermal resistance, ja tqfp-48 56.5 c/w note: (1) for preamp driving vga. (2) referenced to best fit db-linear curve.
VCA2612 3 sbos117c www.ti.com pin configuration 1v dd a channel a +supply (+5v) 2 nc do not connect 3 nc do not connect 4 vca in na channel a vca negative input 5 vca in pa channel a vca positive input 6lnp out na channel a lnp negative output 7lnp out pa channel a lnp positive output 8 swfba channel a switched feedback output 9 fba channel a feedback output 10 comp1a channel a frequency compensation 1 11 comp2a channel a frequency compensation 2 12 lnp in na channel a lnp inverting input 13 lnp gs3 a channel a lnp gain strap 3 14 lnp gs2 a channel a lnp gain strap 2 15 lnp gs1 a channel a lnp gain strap 1 16 lnp in pa channel a lnp noninverting input 17 v dd r +supply for internal reference (+5v) 18 v bias 0.01 f bypass to ground 19 v cm 0.01 f bypass to ground 20 gndr ground for internal reference 21 lnp in pb channel b lnp noninverting input 22 lnp gs1 b channel b lnp gain strap 1 23 lnp gs2 b channel b lnp gain strap 2 24 lnp gs3 b channel b lnp gain strap 3 25 lnp in nb channel b lnp inverting input 26 comp2b channel b frequency compensation 2 27 comp1b channel b frequency compensation 1 28 fbb channel b feedback output 29 swfbb channel b switched feedback output 30 lnp out pb channel b lnp positive output 31 lnp out nb channel b lnp negative output 32 vca in pb channel b vca positive input 33 vca in nb channel b vca negative input 34 nc do not connect 35 nc do not connect 36 v dd b channel b +analog supply (+5v) 37 gndb channel b analog ground 38 vca out nb channel b vca negative output 39 vca out pb channel b vca positive output 40 mgs 3 maximum gain select 3 (lsb) 41 mgs 2 maximum gain select 2 42 mgs 1 maximum gain select 1 (msb) 43 vca cntl vca control voltage 44 vca in sel vca input select, hi = external 45 fbsw cntl feedback switch control: hi = on 46 vca out pa channel a vca positive output 47 vca out na channel a vca negative output 48 gnda channel a analog ground pin designator description pin designator description pin descriptions 36 35 34 33 32 31 30 29 28 27 26 25 v dd b nc nc vca in nb vca in pb lnp out nb lnp out pb swfbb fbb comp1b comp2b lnp in nb gnda vca out na vca out pa fbsw cntl vca in sel vca cntl mgs 1 mgs 2 mgs 3 vca out pb vca out nb gndb lnp gs3 a lnp gs2 a lnp gs1 a lnp in pa v dd r v bias v cm gndr lnp in pb lnp gs1 b lnp gs2 b lnp gs3 b 1 2 3 4 5 6 7 8 9 10 11 12 v dd a nc nc vca in na vca in pa lnp out na lnp out pa swfba fba comp1a comp2a lnp in na 48 47 46 45 44 43 42 41 40 39 38 13 14 15 16 17 18 19 20 21 22 23 37 24 VCA2612
VCA2612 4 sbos117c www.ti.com typical characteristics at t a = +25 c, v dda = v ddb = v ddr = +5v, load resistance = 500 ? on each output to ground, mgs = 011, lnp = 22db and f in = 5mhz, unless otherwise noted. the input to the preamp (lnp) is single-ended, and the output from the vca is single-ended unless otherwise noted. this results in a 6db reduction in signal amplitude compared to differential operation. gain vs vca cntl vca cntl (v) 0.2 1.2 1.0 0.4 0.6 0.8 1.8 2.0 2.2 1.6 1.4 2.4 2.6 2.8 3.0 gain (db) 65 60 55 50 45 40 35 30 25 20 15 mgs = 111 mgs = 110 mgs = 101 mgs = 100 mgs = 011 mgs = 010 mgs = 001 mgs = 000 gain error vs temperature vca cntl (v) 0.2 1.0 1.2 0.8 0.4 0.6 2.0 2.2 1.4 1.6 1.8 2.4 2.6 2.8 3.0 gain error (db) 2.0 1.5 1.0 0.5 0 C 0.5 C 1.0 C 1.5 C 2.0 +25 c C 40 c +85 c gain error vs vca cntl vca cntl (v) 0.2 1.0 1.2 0.8 0.4 0.6 2.0 2.2 1.4 1.6 1.8 2.4 2.6 2.8 3.0 gain error (db) 2.0 1.5 1.0 0.5 0 C 0.5 C 1.0 C 1.5 C 2.0 10mhz 1mhz 5mhz gain error vs vca cntl vca cntl (v) 0.2 1.0 1.2 0.8 0.4 0.6 2.0 2.2 1.4 1.6 1.8 2.4 2.6 2.8 3.0 gain error (db) 2.0 1.5 1.0 0.5 0 C 0.5 C 1.0 C 1.5 C 2.0 mgs = 011 mgs = 000 mgs = 111 gain match: cha to chb, vca cntl = 0.2v delta gain (db) C 0.5 C 0.4 C 0.3 C 0.2 C 0.1 0.0 0.1 0.2 0.3 0.4 0.5 units 100 90 80 70 60 50 40 30 20 10 0 gain match: cha to chb, vca cntl = 3.0v delta gain (db) C 0.5 C 0.4 C 0.3 C 0.2 C 0.1 0.0 0.1 0.2 0.3 0.4 0.5 units 100 90 80 70 60 50 40 30 20 10 0
VCA2612 5 sbos117c www.ti.com typical characteristics (cont.) at t a = +25 c, v dda = v ddb = v ddr = +5v, load resistance = 500 ? on each output to ground, mgs = 011, lnp = 22db and f in = 5mhz, unless otherwise noted. the input to the preamp (lnp) is single-ended, and the output from the vca is single-ended unless otherwise noted. this results in a 6db reduction in signal amplitude compared to differential operation. gain vs frequency (pre-amp) frequency (mhz) 0.1 1 10 100 gain (db) 30 25 20 15 10 5 0 lnp = 25db lnp = 22db lnp = 17db lnp = 5db gain vs frequency (vca and pga, vca cntl = 0.2v) frequency (mhz) 0.1 1 10 100 gain (db) 5.0 4.0 3.0 2.0 1.0 0.0 C 1.0 C 2.0 C 3.0 C 4.0 C 5.0 mgs = 111 mgs = 100 mgs = 011 mgs = 000 gain vs frequency (vca and pga, vca cntl = 3.0v) frequency (mhz) 0.1 1 10 100 gain (db) 45 40 35 30 25 20 15 10 5 0 mgs = 111 mgs = 100 mgs = 011 mgs = 000 gain vs frequency (vca cntl = 3.0v) frequency (mhz) 0.1 1 10 100 gain (db) 60 50 40 30 20 10 0 lnp = 25db lnp = 22db lnp = 5db lnp = 17db gain vs frequency (lnp = 22db) frequency (mhz) 0.1 1 10 100 gain (db) 60 50 40 30 20 10 0 vca cntl = 3.0v vca cntl = 1.6v vca cntl = 0.2v output referred noise vs vca cntl vca cntl (v) 0 1.0 1.2 0.4 0.6 0.8 1.8 2.0 1.4 1.6 2.2 2.4 2.6 2.8 3.0 noise (nv/ hz) 1800 1600 1400 1200 1000 800 600 400 200 0 r s = 50 ? mgs = 111 mgs = 011
VCA2612 6 sbos117c www.ti.com typical characteristics (cont.) at t a = +25 c, v dda = v ddb = v ddr = +5v, load resistance = 500 ? on each output to ground, mgs = 011, lnp = 22db and f in = 5mhz, unless otherwise noted. the input to the preamp (lnp) is single-ended, and the output from the vca is single-ended unless otherwise noted. this results in a 6db reduction in signal amplitude compared to differential operation. input referred noise vs r s r s ( ? ) 1 10 100 1000 noise (nv hz 10.0 1.0 0.1 noise figure vs r s (vca cntl = 3.0v) r s ( ? ) 10 100 1000 noise figure (db) 11 10 9 8 7 6 5 4 3 2 1 0 noise figure vs vca cntl vca cntl (v) noise figure (db) 30 25 20 15 10 5 0 0.2 1.0 1.2 0.4 0.6 0.8 1.8 2.0 1.4 1.6 2.2 2.4 2.6 2.8 3.0 input referred noise vs vca cntl vca cntl (v) 0.2 1.0 1.2 0.4 0.6 0.8 1.8 2.0 1.4 1.6 2.2 2.4 2.6 2.8 3.0 noise (nv/ hz) 24 22 20 18 16 14 12 10 8 6 4 2 0 mgs = 011 mgs = 111 r s = 50 ? lnp vs frequency (differential, 2v pp ) frequency (mhz) 0.1 1 10 100 harmonic distortion (dbc) C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 3rd harmonic 2nd harmonic lnp vs frequency (single-ended, 1v pp ) frequency (mhz) 0.1 1 10 100 harmonic distortion (dbc) C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 2nd harmonic 3rd harmonic
VCA2612 7 sbos117c www.ti.com typical characteristics (cont.) at t a = +25 c, v dda = v ddb = v ddr = +5v, load resistance = 500 ? on each output to ground, mgs = 011, lnp = 22db and f in = 5mhz, unless otherwise noted. the input to the preamp (lnp) is single-ended, and the output from the vca is single-ended unless otherwise noted. this results in a 6db reduction in signal amplitude compared to differential operation. harmonic distortion vs frequency (differential, 2v pp , mgs = 000) frequency (mhz) 0.1 1 10 harmonic distortion (dbc) C 40 C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 C 85 C 90 vca cntl = 0.2v, h2 vca cntl = 0.2v, h3 vca cntl = 3.0v, h2 vca cntl = 3.0v, h3 harmonic distortion vs frequency (differential, 2v pp , mgs = 011) frequency (hz) 0.1 1 10 harmonic distortion (dbc) C 40 C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 C 85 C 90 vca cntl = 0.2v, h2 vca cntl = 0.2v, h3 vca cntl = 3.0v, h2 vca cntl = 3.0v, h3 harmonic distortion vs frequency (differential, 2v pp , mgs = 111) frequency (mhz) 0.1 1 10 harmonic distortion (dbc) C 30 C 35 C 40 C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 vca cntl = 0.2v, h2 vca cntl = 0.2v, h3 vca cntl = 3.0v, h2 vca cntl = 3.0v, h3 harmonic distortion vs frequency (single-ended, 1v pp , mgs = 000) frequency (mhz) 0.1 1 10 harmonic distortion (dbc) C 40 C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 C 85 C 90 vca cntl = 0.2v, h2 vca cntl = 0.2v, h3 vca cntl = 3.0v, h2 vca cntl = 3.0v, h3 harmonic distortion vs frequency (single-ended, 1v pp , mgs = 011) frequency (mhz) 0.1 1 10 harmonic distortion (dbc) C 40 C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 C 85 C 90 vca cntl = 0.2v, h2 vca cntl = 0.2v, h3 vca cntl = 3.0v, h2 vca cntl = 3.0v, h3 harmonic distortion vs frequency (single-ended, 1v pp , mgs = 111) frequency (mhz) 0.1 1 10 harmonic distortion (dbc) C 30 C 35 C 40 C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 C 85 vca cntl = 0.2v, h2 vca cntl = 0.2v, h3 vca cntl = 3.0v, h2 vca cntl = 3.0v, h3
VCA2612 8 sbos117c www.ti.com typical characteristics (cont.) at t a = +25 c, v dda = v ddb = v ddr = +5v, load resistance = 500 ? on each output to ground, mgs = 011, lnp = 22db and f in = 5mhz, unless otherwise noted. the input to the preamp (lnp) is single-ended, and the output from the vca is single-ended unless otherwise noted. this results in a 6db reduction in signal amplitude compared to differential operation. C 1db compression vs vca cntl vca cntl (v) 0.2 1.0 1.2 0.4 0.6 0.8 1.6 1.8 2.0 2.2 1.4 2.4 2.6 3.0 2.8 p in (dbm) 0 C 5 C 10 C 15 C 20 C 25 C 30 C 35 C 40 3rd-order intercept vs vca cntl vca cntl (v) 0.2 1.0 1.2 0.4 0.6 0.8 1.6 1.8 2.0 2.2 1.4 2.4 2.6 3.0 2.8 ip3 (dbm) 0 C 5 C 10 C 15 C 20 C 25 C 30 C 35 C 40 C 45 C 50 harmonic distortion vs vca cntl (differential, 2v pp ) vca cntl (v) 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 harmonic distortion (dbc) C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 mgs = 000, h2 mgs = 011, h2 mgs = 111, h2 mgs = 000, h3 mgs = 011, h3 mgs = 111, h3 harmonic distortion vs vca cntl (single-ended, 1v pp ) vca cntl (v) 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 harmonic distortion (dbc) C 45 C 50 C 55 C 60 C 65 C 70 C 75 C 80 mgs = 000, h2 mgs = 011, h2 mgs = 111, h2 mgs = 000, h3 mgs = 011, h3 mgs = 111, h3 intermodulation distortion (differential, 2v pp , f = 10mhz) frequency (mhz) 9.98 9.96 10 10.2 10.4 power (dbfs) C 5 C 15 C 25 C 35 C 45 C 55 C 65 C 75 C 85 C 95 C 105 intermodulation distortion (single-ended, 1v pp , f = 10mhz) frequency (mhz) 9.98 9.96 10 10.2 10.4 power (dbfs) C 5 C 15 C 25 C 35 C 45 C 55 C 65 C 75 C 85 C 95 C 105
VCA2612 9 sbos117c www.ti.com typical characteristics (cont.) at t a = +25 c, v dda = v ddb = v ddr = +5v, load resistance = 500 ? on each output to ground, mgs = 011, lnp = 22db and f in = 5mhz, unless otherwise noted. the input to the preamp (lnp) is single-ended, and the output from the vca is single-ended unless otherwise noted. this results in a 6db reduction in signal amplitude compared to differential operation. cmrr vs frequency (lnp only) frequency (mhz) 0.1 1 10 100 cmrr (db) 0 C 10 C 20 C 30 C 40 C 50 C 60 C 70 C 80 pulse response (bursts) (differential, vca cntl = 3.0v, mgs = 111) 200ns/div output 500mv/div input 1mv/div overload recovery (differential, vca cntl = 3.0v, mgs = 111) input 1mv/div output 1v/div 200ns/div gain response (differential, vca cntl pulsed, mgs = 111) output 500mv/div input 2v/div 100ns/div cmrr vs frequency (vca only) frequency (mhz) 0.1 1 10 100 cmrr (db) 0 C 10 C 20 C 30 C 40 C 50 C 60 C 70 C 80 C 90 vca cntl = 0.2v vca cntl = 1.4v vca cntl = 3.0v cross talk vs frequency (single-ended, 1vp-p, mgs = 011) frequency (mhz) 1 10 100 cross talk (db) 0 C 10 C 20 C 30 C 40 C 50 C 60 C 70 C 80 C 90 vca cntrl = 0v vca cntrl = 1.5v vca cntrl = 3.0v
VCA2612 10 sbos117c www.ti.com typical characteristics (cont.) at t a = +25 c, v dda = v ddb = v ddr = +5v, load resistance = 500 ? on each output to ground, mgs = 011, lnp = 22db and f in = 5mhz, unless otherwise noted. the input to the preamp (lnp) is single-ended, and the output from the vca is single-ended unless otherwise noted. this results in a 6db reduction in signal amplitude compared to differential operation. 80 79.5 79 78.5 78 77.5 77 76.5 76 i cc vs temperature temperature ( c) C 40 C 10 5 C 25 35 50 20 65 80 95 i cc (ma) group delay vs frequency frequency (mhz) 1 10 100 group delay (ns) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 vca cntl = 3.0v vca cntl = 0.2v C 45 C 40 C 35 C 30 C 25 C 20 C 15 C 10 C 5 0 5 10 psrr vs frequency frequency (hz) 10 1k 100 100k 1m 10k 10m psrr (db)
VCA2612 11 sbos117c www.ti.com vca overview the magnitude of the differential vca input signal (from the lnp or an external source) is reduced by a programmable attenuation factor, set by the analog vca control voltage (vca cntl ) at pin 43. the maximum attenuation factor is further programmable by using the three mgs bits (pins 40- 42). figure 3 illustrates this dual-adjustable characteristic. internally, the signal is attenuated by having the analog vca cntl vary the channel resistance of a set of shunt- connected fet transistors. the mgs bits effectively adjust the overall size of the shunt fet by switching parallel components in or out under logic control. at any given maximum gain setting, the analog variable gain characteris- tic is linear in db as a function of the control voltage, and is created as a piecewise approximation of an ideal db-linear transfer function. the vca gain control circuitry is common to both channels of the VCA2612. figure 1. simplified block diagram of the VCA2612. figure 2. recommended circuit for coupling an external signal into the vca inputs. 0 C 24 vca attenuation (db) C 45 control voltage 0 maximum attenuation minimum attenuation 3.0v figure 3. swept attenuator characteristic. theory of operation the VCA2612 is a dual-channel system consisting of three primary blocks: a low noise preamplifier (lnp), a voltage controlled attenuator (vca), and a programmable gain amplifier (pga). for greater system flexibility, an onboard multiplexer is provided for the vca inputs, selecting either the lnp outputs or external signal inputs. figure 1 shows a simplified block diagram of the dual-channel system. lnp overview the lnp input may be connected to provide active-feedback signal termination, achieving lower system noise perfor- mance than conventional passive shunt termination. even lower noise performance is obtained if signal termination is not required. the unterminated lnp input impedance is 600k ? . the lnp can process fully differential or single- ended signals in each channel. differential signal processing results in significantly reduced 2nd-harmonic distortion and improved rejection of common-mode and power supply noise. the first gain stage of the lnp is ac-coupled into its output buffer with a 44 s time constant (3.6khz high-pass charac- teristic). the buffered lnp outputs are designed to drive the succeeding vca directly or, if desired, external loads as low as 135 ? with minimal impact on signal distortion. the lnp employs very low impedance local feedback to achieve stable gain with the lowest possible noise and distortion. four pin-programmable gain settings are available: 5db, 17db, 22db, and 25db. additional intermediate gains can be programmed by adding trim resistors between the gain strap programming pins. the common-mode dc level at the lnp output is nominally 2.5v, matching the input common-mode requirement of the vca for simple direct coupling. when external signals are fed to the vca, they should also be set up with a 2.5vdc common-mode level. figure 2 shows a circuit that demon- strates the recommended coupling method using an external op amp. the v cm node shown in the drawing is the v cm output (pin 19). typical r and c values are shown, yielding a high-pass time constant similar to that of the lnp. if a different common-mode referencing method is used, it is important that the common-mode level be within 10mv of the v cm output for proper operation. v cm (+2.5v) 1k ? 1k ? 47nf to vca in input signal vca lnp channel a input vca control pga channel a output external in a maximum gain select mgs analog control vca lnp channel b input pga channel b output external in b
VCA2612 12 sbos117c www.ti.com the VCA2612 includes a built-in reference, common to both channels, to supply a regulated voltage for critical areas of the circuit. this reduces the susceptibility to power supply variation, ripple, and noise. in addition, separate power supply and ground connections are provided for each chan- nel and for the reference circuitry, further reducing interchannel cross-talk. further details regarding the design, operation and use of each circuit block are provided in the following sections. low noise preamplifier (lnp) detail the lnp is designed to achieve a low noise figure, especially when employing active termination. figure 4 is a simplified schematic of the lnp, illustrating the differential input and output capability. the input stage employs low resistance local feedback to achieve stable low noise, low distortion performance with very high input impedance. normally, low noise circuits exhibit high power consumption due to the large bias currents required in both input and output stages. the lnp uses a patented technique that combines the input and output stages such that they share the same bias current. transistors q 4 and q 5 amplify the signal at the gate- source input of q 4 , the +in side of the lnp. the signal is further amplified by the q 1 and q 2 stage, and then by the final q 3 and r l gain stage, which uses the same bias current as the input devices q 4 and q 5 . devices q 6 through q 10 play the same role for signals on the C in side. the differential gain of the lnp is given in equation (1): gain r r l s =? ? ? ? ? ? ? 2 r l 93 ? r s1 105 ? q 3 q 4 q 5 q 2 q 1 r s2 34 ? r s3 17 ? lnp gs2 lnp in p lnp in n to bias circuitry lnp gs1 lnp gs3 r l 93 ? comp2a v dd comp1a lnp out n lnp out p buffer buffer q 8 q 7 to bias circuitry q 6 q 9 q 10 r w r w c comp (external capacitor) figure 4. schematic of the low noise preamplifier (lnp). (1) pga overview and overall device characteristics the differential output of the vca attenuator is then amplified by the pga circuit block. this post-amplifier is programmed by the same mgs bits that control the vca attenuator, yielding an overall swept-gain amplifier characteristic in which the vca ? pga gain varies from 0db (unity) to a program- mable peak gain of 24db, 27db, 30db, 33db, 36db, 39db, 42db, or 45db. the gain vs vca cntl curve on page 4 shows the composite gain control characteristic of the entire VCA2612. setting vca cntl to 3.0v causes the digital mgs gain control to step in 3db increments. setting vca cntl to 0v causes all the mgs-controlled gain curves to converge at one point. the gain at the convergence point is the lnp gain less 6db, because the measurement setup looks at only one side of the differential pga output, resulting in 6db lower signal amplitude. additional features overview overload protection stages are placed between the attenua- tor and the pga, providing a symmetrically clipped output whenever the input becomes large enough to overload the pga. a comparator senses the overload signal amplitude and substitutes a fixed dc level to prevent undesirable overload recovery effects. as with the previous stages, the vca is ac-coupled into the pga. in this case, the coupling time constant varies from 5 s at the highest gain (45db) to 59 s at the lowest gain (25db).
VCA2612 13 sbos117c www.ti.com lnp gain (db) input-referred output-referred 25 1.54 2260 22 1.59 1650 17 1.82 1060 5 4.07 597 the lnp is capable of generating a 2v pp differential signal. the maximum signal at the lnp input is therefore 2v pp divided by the lnp gain. an input signal greater than this would exceed the linear range of the lnp, an especially important consideration at low lnp gain settings. active feedback with the lnp one of the key features of the lnp architecture is the ability to employ active-feedback termination to achieve superior noise performance. active feedback termination achieves a lower noise figure than conventional shunt termination, es- sentially because no signal current is wasted in the termina- tion resistor itself. another way to understand this is as follows: consider first that the input source, at the far end of the signal cable has a cable-matching source resistance of r s . using conventional shunt termination at the lnp input, a second terminating resistor of value r s is connected to ground. therefore, the signal loss is 6db due to the voltage divider action of the series and shunt r s resistors. the effective source resistance has been reduced by the same factor of 2, but the noise contribution has been reduced by only the 2, only a 3db reduction. therefore, the net theoreti- cal snr degradation is 3db, assuming a noise-free amplifier input. (in practice, the amplifier noise contribution will de- grade both the unterminated and the terminated noise fig- ures, somewhat reducing the distinction between them.) see figure 5 for an amplifier using active feedback. this diagram appears very similar to a traditional inverting ampli- fier. however, the analysis is somewhat different because the gain a in this case is not a very large open-loop op amp gain; rather, it is the relatively low and controlled gain of the lnp itself. thus, the impedance at the inverting amplifier terminal will be reduced by a finite amount, as given in the familiar relationship of equation (3): r r a in f = + ( ) 1 where r f is the feedback resistor (supplied externally be- tween the lnp in p and fb terminals for each channel), a is the user-selected gain of the lnp, and r in is the resulting amplifier input impedance with active feedback. in this case, unlike the conventional termination above, both the signal voltage and the r s noise are attenuated by the same factor it is also possible to create other gain settings by connecting an external resistor between lnpg s1 on one side, and lnpg s2 and/or lnpg s3 on the other. in that case, the internal resistor values shown in figure 4 should be com- bined with the external resistor to calculate the effective value of r s for use in equation (1). the resulting expression for external resistor value is given in equation (2). r rr r r gainrr gain r r ext s l fix l s fix s l = +? ? 22 2 11 1 C C where r ext is the externally selected resistor value needed to achieve the desired gain setting, r s1 is the fixed parallel resistor in figure 4, and r fix is the effective fixed value of the remaining internal resistors: r s2 , r s3 , or (r s2 || r s3 ) depend- ing on the pin connections. note that the best process and temperature stability will be achieved by using the pre-programmed fixed gain options of table i, since the gain is then set entirely by internal resistor ratios, which are typically accurate to 0.5%, and track quite well over process and temperature. when combining exter- nal resistors with the internal values to create an effective r s value, note that the internal resistors have a typical tempera- ture coefficient of +700ppm/ c and an absolute value toler- ance of approximately 5%, yielding somewhat less predict- able and stable gain settings. with or without external resis- tors, the board layout should use short gain strap connec- tions to minimize parasitic resistance and inductance effects. the overall noise performance of the VCA2612 will vary as a function of gain. table ii shows the typical input- and output-referred noise densities of the entire VCA2612 for maximum vca and pga gain; i.e., vca cntl set to 3.0v and all mgs bits set to 1 . note that the input-referred noise values include the contribution of a 50 ? fixed source imped- ance, and are therefore somewhat larger than the intrinsic input noise. as the lnp gain is reduced, the noise contribu- tion from the vca/pga portion becomes more significant, resulting in higher input-referred noise. however, the output- referred noise, which is indicative of the overall snr at that gain setting, is reduced. noise (nv/ hz) table ii. noise performance for mgs = 111 and vca cntl = 3.0v. lnp pin strapping lnp gain (db) lnpg s1 , lnpg s2 , lnpg s3 connected together 25 lnpg s1 connected to lnpg s3 22 lnpg s1 connected to lnpg s2 17 all pins open 5 table i. pin strappings of the lnp for various gains. (3) (2) where r l is the load resistor in the drains of q 3 and q 8 , and r s is the resistor connected between the sources of the input transistors q 4 and q 7 . the connections for various r s com- binations are brought out to device pins lnpg s1 , lnpg s2, and lnpg s3 (pins 13-15 for channel a, 22-24 for channel b). these gain strap pins allow the user to establish one of four fixed lnp gain options as shown in table i. to preserve the low noise performance of the lnp, the user should take care to minimize resistance in the input lead. a parasitic resistance of only 10 ? will contribute 0.4nv/ hz .
VCA2612 14 sbos117c www.ti.com r f a r in r in = r s r s r s = r s lnp in r f 1 + a active feedback a conventional cable termination figure 5. configurations for active feedback and conven- tional cable termination. vca noise = 3.8nv hz, lnp gain = 20db source impedance ( ? ) 0 300 100 200 500 400 600 700 800 900 1000 noise figure (db) 9 8 7 6 5 4 3 2 1 0 6.0e-10 8.0e-10 1.0e-09 1.2e-09 1.4e-09 1.6e-09 1.8e-09 2.0e-09 lnp noise nv/ hz source impedance ( ? ) 0 300 100 200 500 400 600 700 900 1000 800 noise figure (db) 14 12 10 8 6 4 2 0 vca noise = 3.8nv hz, lnp gain = 20db lnp noise nv/ hz 6.0e-10 8.0e-10 1.0e-09 1.2e-09 1.4e-09 1.6e-09 1.8e-09 2.0e-09 figure 6. noise figure for active termination. figure 7. noise figure for conventional termination. figure 8. low frequency lnp time constants. of two (6db) before being re-amplified by the a gain setting. this avoids the extra 3db degradation due to the square-root effect described above, the key advantage of the active termination technique. as mentioned above, the previous explanation ignored the input noise contribution of the lnp itself. also, the noise contribution of the feedback resistor must be included for a completely correct analysis. the curves given in figures 6 and 7 allow the VCA2612 user to compare the achievable noise figure for active and conventional termination methods. the left-most set of data points in each graph give the results for typical 50 ? cable termination, showing the worst noise figure but also the greatest advantage of the active feedback method. a switch, controlled by the fbsw cntl signal on pin 45, enables the user to reduce the feedback resistance by adding an additional parallel component, connected be- tween the lnp in p and swfb terminals. the two different values of feedback resistance will result in two different values of active-feedback input resistance. thus, the active- feedback impedance can be optimized at two different lnp gain settings. the switch is connected at the buffered output of the lnp and has an on resistance of approximately 1 ? . when employing active feedback, the user should be careful to avoid low-frequency instability or overload problems. figure 8 illustrates the various low-frequency time constants. referring again to the input resistance calculation of equa- tion (3), and considering that the gain term a falls off below 3.6khz, it is evident that the effective lnp input impedance will rise below 3.6khz, with a dc limit of approximately r f . to avoid interaction with the feedback pole/zero at low frequencies, and to avoid the higher signal levels resulting from the rising impedance characteristic, it is recommended that the external r f c c time constant be set to about 5 s. r s 1m ? c c c f 0.001 f v cm r f 44pf buffer 1m ? v cm lnp out n lnp out p 44pf gain stage (vca) lnp buffer
VCA2612 15 sbos117c www.ti.com achieving the best active feedback architecture is difficult with conventional op amp circuit structures. the overall gain a must be negative in order to close the feedback loop, the input impedance must be high to maintain low current noise and good gain accuracy, but the gain ratio must be set with very low value resistors to maintain good voltage noise. using a two-amplifier configuration (noninverting for high impedance plus inverting for negative feedback reasons) results in excessive phase lag and stability problems when the loop is closed. the VCA2612 uses a patented architec- ture that achieves these requirements, with the additional benefits of low power dissipation and differential signal han- dling at both input and output. for greatest flexibility and lowest noise, the user may wish to shape the frequency response of the lnp. the comp1 and comp2 pins for each channel (pins 10 and 11 for channel a, pins 26 and 27 for channel b) correspond to the drains of q 3 and q 8 in figure 4. a capacitor placed between these pins will create a single-pole low-pass response, in which the effective r of the rc time constant is approximately 186 ? . compensation when using active feedback the typical open-loop gain versus frequency characteristic for the lnp is shown in figure 9. the C 3db bandwidth is approximately 180mhz and the phase response is such that when feedback is applied the lnp will exhibit a peaked response or might even oscillate. one method for compen- sating for this undesirable behavior is to place a compensa- tion capacitor at the input to the lnp, as shown in figure 10. this method is effective when the desired C 3db bandwidth is much less than the open-loop bandwidth of the lnp. this compensation technique also allows the total compensation capacitor to include any stray or cable capacitance that is 25db gain C 3db bandwidth 180mhz output input r f r i c a associated with the input connection. equation 4 relates the bandwidth to the various impedances that are connected to the lnp. bw a1r r 2pc(r )(r ) if if = + ( ) + (4) lnp output buffer the differential lnp output is buffered by wideband class ab voltage followers which are designed to drive low impedance loads. this is necessary to maintain lnp gain accuracy, since the vca input exhibits gain-dependent input imped- ance. the buffers are also useful when the lnp output is brought out to drive external filters or other signal processing circuitry. good distortion performance is maintained with buffer loads as low as 135 ? . as mentioned previously, the buffer inputs are ac-coupled to the lnp outputs with a 3.6khz high-pass characteristic, and the dc common-mode level is maintained at the correct v cm for compatibility with the vca input. voltage-controlled attenuator (vca) detail the vca is designed to have a db-linear attenuation charac- teristic, i.e. the gain loss in db is constant for each equal increment of the vca cntl control voltage. see figure 11 for a diagram of the vca. the attenuator is essentially a variable voltage divider consisting of one series input resistor, r s , and ten identical shunt fets, placed in parallel and controlled by sequentially activated clipping amplifiers. each clipping amplifier can be thought of as a specialized voltage comparator with a soft transfer character- istic and well-controlled output limit voltages. the reference voltages v1 through v10 are equally spaced over the 0v to 3.0v control voltage range. as the control voltage rises through the input range of each clipping amplifier, the ampli- fier output will rise from 0v (fet completely on ) to v cm C v t (fet nearly off ), where v cm is the common source voltage and v t is the threshold voltage of the fet. as each fet approaches its off state and the control voltage continues to rise, the next clipping amplifier/fet combination takes over for the next portion of the piecewise-linear attenuation characteristic. thus, low control voltages have most of the fets turned on , while high control voltages have most turned off . each fet acts to decrease the shunt resistance of the voltage divider formed by r s and the parallel fet network. the attenuator is comprised of two sections, with five parallel clipping amplifier/fet combinations in each. special refer- ence circuitry is provided so that the (v cm C v t ) limit voltage will track temperature and ic process variations, minimizing the effects on the attenuator control characteristic. in addition to the analog vca cntl gain setting input, the attenuator architecture provides digitally programmable ad- justment in eight steps, via the three maximum gain setting (mgs) bits. these adjust the maximum achievable gain figure 9. open-loop gain characteristic of lnp. figure 10. lnp with compensation capacitor.
VCA2612 16 sbos117c www.ti.com r s attenuator input attenuator output a1 - a10 attenuator stages control input q 1 v cm 0db C 4.5db q 2 q 3 c 1 v1 q 4 q 5 q s c1 - c10 clipping amplifiers attenuation characteristic of individual fets q 6 q 7 q 8 q 9 q 10 c 2 v2 v cm -v t 0 v1 v2 v3 v4 v5 v6 v7 v8 v9 v10 characteristic of attenuator control stage output overall control characteristics of attenuator C 4.5db 0db 0.3v 3v control signal c 3 v3 c 4 v4 c 5 v5 c 6 v6 c 7 v7 c 8 v8 c 9 v9 c 10 v10 a1 a2 a3 a4 a5 a6 a7 a8 a9 a10 figure 11. piecewise approximation to logarithmic control characteristics. (corresponding to minimum attenuation in the vca, with vca cntl = 3.0v) in 3db increments. this function is accom- plished by providing multiple fet sub-elements for each of the q 1 to q 10 fet shunt elements shown in figure 11. in the simplified diagram of figure 12, each shunt fet is shown as two sub-elements, q na and q nb . selector switches, driven by the mgs bits, activate either or both of the sub-element fets to adjust the maximum r on and thus achieve the stepped attenuation options. the vca can be used to process either differential or single- ended signals. fully differential operation will reduce 2nd- harmonic distortion by about 10db for full-scale signals.
VCA2612 17 sbos117c www.ti.com r s q 1a a1 b1 vcm input output programmable attenuator section b2 q 1b q 2a a2 q 2b q 3a a3 q 3b q 4a a4 q 4b q 5a a5 q 5b figure 12. programmable attenuator section. input impedance of the vca will vary with gain setting, due to the changing resistances of the programmable voltage divider structure. at large attenuation factors (i.e., low gain settings), the impedance will approach the series resistor value of approximately 135 ? . as with the lnp stage, the vca output is ac-coupled into the pga. this means that the attenuation-dependent dc com- mon-mode voltage will not propagate into the pga, and so the pga s dc output level will remain constant. finally, note that the vca cntl input consists of fet gate inputs. this provides very high impedance and ensures that multiple VCA2612 devices may be connected in parallel with no significant loading effects. the nominal voltage range for the vca cntl input spans from 0v to 3v. over driving this input ( 5v) does not affect the performance. overload recovery circuitry detail with a maximum overall gain of 70db, the VCA2612 is prone to signal overloading. such a condition may occur in either the lnp or the pga depending on the various gain and attenuation settings available. the lnp is designed to pro- duce low-distortion outputs as large as 1v pp single-ended (2v pp differential). therefore the maximum input signal for linear operation is 2v pp divided by the lnp differential gain setting. clamping circuits in the lnp ensure that larger input amplitudes will exhibit symmetrical clipping and short recov- ery times. the vca itself, being basically a voltage divider, is intrinsically free of overload conditions. however, the pga post-amplifier is vulnerable to sudden overload, particularly at high gain settings. rapid overload recovery is essential in many signal processing applications such as ultrasound imaging. a special comparator circuit is provided at the pga input which detects overrange signals (detection level de- pendent on pga gain setting). when the signal exceeds the comparator input threshold, the vca output is blocked and an appropriate fixed dc level is substituted, providing fast and clean overload recovery. the basic architecture is shown in figure 13. both high and low overrange conditions are sensed and corrected by this circuit. figures 14 and 15 show typical overload recovery wave- forms with mgs = 100, for vca + pga minimum gain (0db) and maximum gain (36db), respectively. lnp gain is set to 25db in both cases. figure 14. overload recovery response for minimum gain. figure 15. overload recovery response for maximum gain. vca cntl = 0.2v, differential, mgs = 100, (0db) 200ns/div 1v/div output input vca cntl = 3.0v, differential, mgs = 100, (36db) 200ns/div 1v/div output input figure 13. overload protection circuitry. comparators e = maximum peak amplitude e a C from vca selection logic pga gain = a output e a
VCA2612 18 sbos117c www.ti.com input overload recovery one of the most important applications for the VCA2612 is processing signals in an ultrasound system. the ultrasound signal flow begins when a large signal is applied to a transducer, which converts electrical energy to acoustic energy. it is not uncommon for the amplitude of the electrical signal that is applied to the transducer to be 50v or greater. to prevent damage, it is necessary to place a protection circuit between the transducer and the VCA2612, as shown in figure 16. care must be taken to prevent any signal from turning the esd diodes on. turning on the esd diodes inside the VCA2612 could cause the input coupling capaci- tor (c c ) to charge to the wrong value. mgs attenuator gain differential attenuator + setting vca cntl = 0v to 3v pga gain diff. pga gain 000 C 24db to 0db 24db 0db to 24db 001 C 27db to 0db 27db 0db to 27db 010 C 30db to 0db 30db 0db to 30db 011 C 33db to 0db 33db 0db to 33db 100 C 36db to 0db 36db 0db to 36db 101 C 39db to 0db 39db 0db to 39db 110 C 42db to 0db 42db 0db to 42db 111 C 45db to 0db 45db 0db to 45db table iii. mgs settings. that setting. therefore, the vca + pga overall gain will always be 0db (unity) when the analog vca cntl input is set to 0v (= maximum attenuation). for vca cntl = 3v (no attenuation), the vca + pga gain will be controlled by the programmed pga gain (24db to 45db in 3db steps). for clarity, the gain and attenuation factors are detailed in table iii. figure 17. simplified block diagram of the pga section within the VCA2612. figure 16. VCA2612 diode bridge protection circuit. r s1 r l r s2 vca out p +in q 11 q 3 q 4 q 5 q 1 v cm q 2 vca out n q 9 q 8 q 13 q 14 q 7 q 6 q 12 v dd v cm r l q 10 C in to bias circuitry to bias circuitry the pga architecture consists of a differential, program- mable-gain voltage to current converter stage followed by transimpedance amplifiers to create and buffer each side of the differential output. the circuitry associated with the voltage to current converter is similar to that previously described for the lnp, with the addition of eight selectable pga gain-setting resistor combinations (controlled by the mgs bits) in place of the fixed resistor network used in the lnp. low input noise is also a requirement of the pga design due to the large amount of signal attenuation which can be inserted between the lnp and the pga. at minimum vca attenuation (used for small input signals) the lnp noise dominates; at maximum vca attenuation (large input signals) the pga noise dominates. note that if the pga output is used single-ended, the apparent gain will be 6db lower. r f c f v dd lnp in p esd diode protection network lnp out n lnp pga post-amplifier detail figure 17 shows a simplified circuit diagram of the pga block. as described previously, the pga gain is programmed with the same mgs bits which control the vca maximum attenu- ation factor. specifically, the pga gain at each mgs setting is the inverse (reciprocal) of the maximum vca attenuation at
package option addendum www.ti.com 10-jun-2014 addendum-page 1 packaging information orderable device status (1) package type package drawing pins package qty eco plan (2) lead/ball finish (6) msl peak temp (3) op temp (c) device marking (4/5) samples VCA2612y/250 active tqfp pfb 48 250 green (rohs & no sb/br) cu nipdau level-2-260c-1 year VCA2612y (1) the marketing status values are defined as follows: active: product device recommended for new designs. lifebuy: ti has announced that the device will be discontinued, and a lifetime-buy period is in effect. nrnd: not recommended for new designs. device is in production to support existing customers, but ti does not recommend using this part in a new design. preview: device has been announced but is not in production. samples may or may not be available. obsolete: ti has discontinued the production of the device. (2) eco plan - the planned eco-friendly classification: pb-free (rohs), pb-free (rohs exempt), or green (rohs & no sb/br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. tbd: the pb-free/green conversion plan has not been defined. pb-free (rohs): ti's terms "lead-free" or "pb-free" mean semiconductor products that are compatible with the current rohs requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. where designed to be soldered at high temperatures, ti pb-free products are suitable for use in specified lead-free processes. pb-free (rohs exempt): this component has a rohs exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. the component is otherwise considered pb-free (rohs compatible) as defined above. green (rohs & no sb/br): ti defines "green" to mean pb-free (rohs compatible), and free of bromine (br) and antimony (sb) based flame retardants (br or sb do not exceed 0.1% by weight in homogeneous material) (3) msl, peak temp. - the moisture sensitivity level rating according to the jedec industry standard classifications, and peak solder temperature. (4) there may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) multiple device markings will be inside parentheses. only one device marking contained in parentheses and separated by a "~" will appear on a device. if a line is indented then it is a continuation of the previous line and the two combined represent the entire device marking for that device. (6) lead/ball finish - orderable devices may have multiple material finish options. finish options are separated by a vertical ruled line. lead/ball finish values may wrap to two lines if the finish value exceeds the maximum column width. important information and disclaimer: the information provided on this page represents ti's knowledge and belief as of the date that it is provided. ti bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. efforts are underway to better integrate information from third parties. ti has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. ti and ti suppliers consider certain information to be proprietary, and thus cas numbers and other limited information may not be available for release. in no event shall ti's liability arising out of such information exceed the total purchase price of the ti part(s) at issue in this document sold by ti to customer on an annual basis.
package option addendum www.ti.com 10-jun-2014 addendum-page 2
tape and reel information *all dimensions are nominal device package type package drawing pins spq reel diameter (mm) reel width w1 (mm) a0 (mm) b0 (mm) k0 (mm) p1 (mm) w (mm) pin1 quadrant VCA2612y/250 tqfp pfb 48 250 330.0 16.4 9.6 9.6 1.5 12.0 16.0 q2 package materials information www.ti.com 21-may-2014 pack materials-page 1
*all dimensions are nominal device package type package drawing pins spq length (mm) width (mm) height (mm) VCA2612y/250 tqfp pfb 48 250 336.6 336.6 31.8 package materials information www.ti.com 21-may-2014 pack materials-page 2
mechanical data mtqf019a january 1995 revised january 1998 post office box 655303 ? dallas, texas 75265 pfb (s-pqfp-g48) plastic quad flatpack 4073176 / b 10/96 gage plane 0,13 nom 0,25 0,45 0,75 seating plane 0,05 min 0,17 0,27 24 25 13 12 sq 36 37 7,20 6,80 48 1 5,50 typ sq 8,80 9,20 1,05 0,95 1,20 max 0,08 0,50 m 0,08 0 7 notes: a. all linear dimensions are in millimeters. b. this drawing is subject to change without notice. c. falls within jedec ms-026

important notice texas instruments incorporated and its subsidiaries (ti) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per jesd46, latest issue, and to discontinue any product or service per jesd48, latest issue. buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. all semiconductor products (also referred to herein as ? components ? ) are sold subject to ti ? s terms and conditions of sale supplied at the time of order acknowledgment. ti warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in ti ? s terms and conditions of sale of semiconductor products. testing and other quality control techniques are used to the extent ti deems necessary to support this warranty. except where mandated by applicable law, testing of all parameters of each component is not necessarily performed. ti assumes no liability for applications assistance or the design of buyers ? products. buyers are responsible for their products and applications using ti components. to minimize the risks associated with buyers ? products and applications, buyers should provide adequate design and operating safeguards. ti does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right relating to any combination, machine, or process in which ti components or services are used. information published by ti regarding third-party products or services does not constitute a license to use such products or services or a warranty or endorsement thereof. use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from ti under the patents or other intellectual property of ti. reproduction of significant portions of ti information in ti data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. ti is not responsible or liable for such altered documentation. information of third parties may be subject to additional restrictions. resale of ti components or services with statements different from or beyond the parameters stated by ti for that component or service voids all express and any implied warranties for the associated ti component or service and is an unfair and deceptive business practice. ti is not responsible or liable for any such statements. buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements concerning its products, and any use of ti components in its applications, notwithstanding any applications-related information or support that may be provided by ti. buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause harm and take appropriate remedial actions. buyer will fully indemnify ti and its representatives against any damages arising out of the use of any ti components in safety-critical applications. in some cases, ti components may be promoted specifically to facilitate safety-related applications. with such components, ti ? s goal is to help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and requirements. nonetheless, such components are subject to these terms. no ti components are authorized for use in fda class iii (or similar life-critical medical equipment) unless authorized officers of the parties have executed a special agreement specifically governing such use. only those ti components which ti has specifically designated as military grade or ? enhanced plastic ? are designed and intended for use in military/aerospace applications or environments. buyer acknowledges and agrees that any military or aerospace use of ti components which have not been so designated is solely at the buyer ' s risk, and that buyer is solely responsible for compliance with all legal and regulatory requirements in connection with such use. ti has specifically designated certain components as meeting iso/ts16949 requirements, mainly for automotive use. in any case of use of non-designated products, ti will not be responsible for any failure to meet iso/ts16949. products applications audio www.ti.com/audio automotive and transportation www.ti.com/automotive amplifiers amplifier.ti.com communications and telecom www.ti.com/communications data converters dataconverter.ti.com computers and peripherals www.ti.com/computers dlp ? products www.dlp.com consumer electronics www.ti.com/consumer-apps dsp dsp.ti.com energy and lighting www.ti.com/energy clocks and timers www.ti.com/clocks industrial www.ti.com/industrial interface interface.ti.com medical www.ti.com/medical logic logic.ti.com security www.ti.com/security power mgmt power.ti.com space, avionics and defense www.ti.com/space-avionics-defense microcontrollers microcontroller.ti.com video and imaging www.ti.com/video rfid www.ti-rfid.com omap applications processors www.ti.com/omap ti e2e community e2e.ti.com wireless connectivity www.ti.com/wirelessconnectivity mailing address: texas instruments, post office box 655303, dallas, texas 75265 copyright ? 2014, texas instruments incorporated

▲Up To Search▲

Price & Availability of VCA2612

	To Download VCA2612 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .