1 video ics vif / sif signal processor for televisions and vcrs BH7370FS the BH7370FS is a vif / sif signal processor that supports the m mode (used in the u.s. and japan). an applica- tion of bicmos process and active filter technology, this ic has been designed with an internal vco, aft, sound band-pass filter, sound-trap and fm demodulator circuit. and thanks to rohm's original automatic adjustment tech- nology, the digital aft circuit, internal tank circuit and filter circuit are all adjustment-free. applications tvs, lcd tvs, and tuner blocks for multimedia devices features 1) internal adjustment-free if tank coil and audio filter. 2) digital aft circuit, for highly precise, highly stable frequencies. 3) the reference signal input from the tuner fixed at 4mhz, eliminating the need for an oscillator. 4) no vco coil is used, allowing for excellent resis- tance to magnetic noise. 5) a pulse count audio detector circuit with excellent s / n and linearity. 6) internal b / w inverter circuit. absolute maximum ratings (ta = 25?) parameter symbol limits unit v cc v pd mw topr c tstg c 7.0 ?15 ~ + 75 ?40 ~ + 150 650 * power supply voltage operating temperature storage temperature * reduced by 6.5mw for each increase in ta of 1 c over 25 c . power dissipation operating conditions (ta = 25?) parameter symbol min. typ. max. unit v cc5v 5.0 v 5.3 4.7 v cc 5.0 v 5.5 4.5 power supply voltage guaranteed operating power supply voltage
2 video ics BH7370FS block diagram pin descriptions 123456789101112 24 23 22 21 20 19 18 17 16 15 14 13 500 100k 100k v dd eq vco lim agc b/w inv ?45 shift sif bpf 500k bpf pll det f count sif trap ref osc ref fil fm dem af amp aft ?fb digital aft + 45 shift video amp vif amp vif amp sound trap rf agc n.c. agc ?adj rf ?agc gnd1 vifa vifb gnd2 osc ?in eco aft ?out af ?out aft ?fb n.c. agc ?flt eq ?flt video ?out pll ?flt fs v cc v dd gnd ?d vo ?4.5m afc vco ?cont 1n.c. 2 agc ?adj 3 rf ?agc 4 gnd1 5 vifa 6 vifb 7 gnd2 8 osc ?in 9 eco 10 aft ?out 11 af ?out 12 aft ?fb 13 vco ? cont 14 afc 15 vo ? 4.5m 16 gnd ? d 17 v dd 18 19 20 21 22 eq ? flt 23 agc ? flt 24 n.c. fs v cc video ? out pll ? flt pin no. pin name function function pin no. pin name adjusting the rf agc delay point rf agc output vif gnd vifa input vifb input sif and vco gnd 4mhz oscillator input reference filter detection aft output audio output fb pin for pll-fll switching between 45.75mhz (u.s.) and 58.75mhz (japan) audio detection filter and audio / video mute switch 2nd sif output cmos ground cmos v dd eq filter if agc filter bipolar v cc f-counter output pll phase detection filter video out
3 video ics BH7370FS input / output circuits n.c. 1 2 3 5 6 7 8 9 10 4 agc adj rf agc ref osc in gnd1 gnd2 aft out vifa vifb eco 0v 2.2v 0v 3.4v 2v 4.5k 7.8k 5k 5k 2k 100k 100 vcc gnd gnd out in out in vcc 1k 1k 7.4k 5k 5k 38.9k 10k 10k 60p 16k 10k 2.6v 100k 1k 100k 1k 10k 1k 10k 30k 20k 10k 7.4k 750 vcc gnd 2 3 5 6 vcc gnd 8 vcc gnd 9 v dd gnd 10 pin name in / out pin no. voltage equivalent circuit function adjusting the rfagc delay point. a fixed resistor (20k w ) is normally fixed between grounds. for greater precision, adjust with a variable resistor (50k w ). internally open rf-agc output (reverse). because of open collector output, gain can be set with an attached resistor (the minimum value for pin 3's maximum sink current is 0.7ma). pin 3 voltage should remain below 7 v. bipolar ground for the vif, agc and video system. bipolar ground for the sif and vco. 4mhz reference oscillator input (input level = 25 - 100mv p-p , frequency precision = 0.1% or less) reference filter detection output. aft output (cmos output). v dd and the ground each have an internal 100k w resistor. output is 1 / 2v dd at the center frequency. if input. use equilibrium input. 0.2v (13k w connection)
4 video ics BH7370FS 11 12 13 14 15 16 af out aftf fb afc gnd d vco cont vo 4.5m 2.2v 2.4v 2.2v 0v out out in 2k 60k 2k 5.66p 11.3p 500 500 500 500 80k 200 100 800 5k 1k 5k 20k 50k 20k 20k 50k vcc gnd 12 10 13 vcc gnd 14 vcc gnd 15 vcc vcc gnd gnd 11 17 v dd 4.5v pin name in / out pin no. voltage equivalent circuit function audio signal output. a de-emphasis constant should normally be attached. the lo range of the aft curve can be expanded by feeding back to pll?il. automatic adjustment fb for the 500khz pulse counter fm demo. attach a capacitor (roughly 4.7 m f). lowering this pin below 0.3v mutes audio and video. 2nd sif output. sound filter characteristics can be changed by connecting this pin to the trap. to reduce color buzzing, attach a 3.5mhz trap. internal impedance is approximately 500 w . attach a buffer if output. c-mos gnd. locate the pattern as far as possible from the bipolar ?gnd. switching the internal vco frequency. high = 45.75mhs (u.s.) (connect to vcc) low = 58.75mhz (japan) (connect to ground) c-mos v dd . cmos radiation can be greatly reduced by positioning a cr filter between this pin and bipolar ?vcc.
5 video ics BH7370FS 19 18 20 fs v cc pll flt 3.0v 5.0v v dd gnd 19 12.5k 1k 1k 300 300 v cc gnd 20 21 22 23 24 video out eq flt n.c. agc flt 2.0v (sync) 2.0v (sync) 4.0v 200 2k 100 1p v cc gnd out 21 200 2k 1p v cc gnd 22 400 v cc gnd 23 output of the f-counter's cmos charge pump. attached time constant of the pll filter. power supply for the entire bipolar system. video output. output via the sound trap, b / w noise inverter, and eq amplifier. eq filter (normally left open). for eq characteristics, use an lcr series resonator to connect this pin to the ground. internally open. attaching the filter time constant for the vif and agc. pin name in / out pin no. voltage equivalent circuit function
6 video ics BH7370FS parameter symbol min. typ. max. unit conditions supply current i cc 50 ma (internal stabilization supply voltage) (v reg ) (2.6) v vif ? v vmin. ?046db m v vo = ?3db input sensitivity v vmax. 100 110 db m max. allowable input level gr 62 70 db agc range v p21 3.2 quiescent video output voltage v vo 1.2 video detection output level v p21sy 1.9 v synehronous signal tip voltage dg 2 5 % video output (dg) dp 1 5 deg video output (dp) g vo4.5 45 db 20log (vo4.5m / vo0.2m) p = 0, p / c = 4, p / s = 14db p = 90db m , 100% white sound trap attenuation i 920 ?6 db s / n v 47 53 db vco free-running frequency ?250 125 + 250 khz v v p-p no signal, v 23 = v cc p = 90db m , am 87.5% mod, 100% white video signal p = 90db m , am 87.5% mod, 3-step video signal v vo = + 1db v vo = 3db range video output s / n white noise threshold voltage v wth 3.6 v cw = 70db m cw = 100db m agc adj = 20k v wcl 2.5 v change in frequency and pin 23 voltage white noise clamping voltage v bth 1.5 v black noise threshold voltage v bcl 2.5 v black noise clamping voltage i p3si 0.4 1.0 ma rf agc max. sink current v rfagc ?0 rf agc delay point aft ? v p10max. 4.0 4.5 v maximum aft voltage v p10min. 0.1 1.0 v minimum aft voltage s t f vco ?80 + 50 khz aft detection sensitivity db agc adj = 20k cw = 45.25mhz cw = 46.25mhz 920khz beat level pll ? pll capture range 1 f cu + 1.0 + 2.0 mhz f cl ?2.0 ?1.0 mhz pll capture range 2 f lu + 1.0 + 2.0 mhz cw = 80db m pll lock range 1 f ll 2.0 ?1.0 mhz pll lock range 2 b 9.0 khz / mv vco control sensitivity sif ? p = 45.75mhz / 90db m s = 41.25mhz / 70db m v smin. ?439 input sensitivity v smax. 75 db m sif max. allowable input level v so 500 mv rms fm detection output level sn af 55 db fm = 400hz, d f = 25khz audio output s / n thd 0.2 1.0 % fm = 400hz, d f = 25khz d f = 12.5khz, am30% v p14 = gnd audio output distortion amr 53 db v vmute 2.5 v db m fm = 400hz, d f = 25khz fm = 400hz, d f = 25khz 5% distortion frequency change muted video output voltage muted audio output voltage v smute 2.2 v v p14 = gnd v 14mute 0.3 v mute start voltage v vo4.5m 10 20 50 mv p-p p = 90db m p / s = 20db, when using fet probe vo4.5m output level v osc 25 100 mv p-p 4mhz oscillator input amr electrical characteristics (unless otherwise noted, ta = 25?, v cc = 5v, p = 45.75mhz)
7 video ics BH7370FS 123456789101112 24 23 22 21 20 19 18 17 16 15 14 13 n.c. 20k 22k agc-flt agc-adj rf-agc v cc gnd1 ifin 4mhz in aftout de.em out gnd2 eco n.c. fs v cc v dd afc gnd-d pll-flt videoout vo-4.5m v cc jpn us mute 0.1 m v23 100 m 0.01 m 0.01 m 0.01 m 0.01 m 0.01 m 1: 1 0.01 m 7.5k 0.1 m 4.7 m 0.22 m 0.01 m 4.7 m 27 m 82p 0.01 m 150 500 100k 100k v dd 5.1k 390 39k eq vco lim agc b / w inv ?45 shift sif bpf 500k bpf pll det f count sif trap ref osc ref fil fm dem af amp aft ?fb digital aft + 45 shift video amp vif amp vif amp sound trap rf agc + + + fig. 1 measurement circuit
8 video ics BH7370FS 123456789101112 24 23 22 21 20 19 18 17 16 15 14 13 n.c. 20k 22k agc-flt agc-adj rf-agc v cc gnd1 ifin 4mhz in aftout de.em out aft-fb gnd2 eco intercarrier n.c. eq fs v cc v dd afc gnd-d pll-flt videoout vo-4.5m v cc jpn us 0.1 m 47 m 100 m 0.01 m 0.01 m 0.01 m 0.01 m 0.01 m 7.5k 3.9k 0.1 m 4.7 m 0.22 m 4.7 m 15 m 139p 0.01 m 1000p 150 500 100k 100k v dd 5.1k 390 47 39k eq vco lim agc b/w inv ?45 shift sif bpf 500k bpf pll det f count sif trap ref osc ref fil fm dem af amp aft ?fb digital aft + 45 shift video amp vif amp vif amp sound trap rf agc + + + saw filter (180p) 5.1k fig. 2 application example
9 video ics BH7370FS ssop-a24 0.15 0.3min. 7.8 0.3 5.4 0.2 1.8 0.1 0.11 1 24 0.36 0.1 10.0 0.2 12 13 0.8 0.15 0.1 external dimensions (units: mm)
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