View LTC1550LCGNTRPBF_8631719.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1 ltc1550l/ltc1551l low noise, switched capacitor regulated voltage inverters the ltc ? 1550l/ltc1551l are switched capacitor charge pump voltage inverters which include internal linear post-regulators to minimize output ripple. the ltc1550l fixed output voltage versions include C 4.1v, C2.5v and C2v with ripple voltages typically below 1mv p-p . the ltc1550l is also available in an adjustable output voltage version. theltc1550l/ltc1551l are ideal for use as bias voltage generators for gaas transmitter fets in portable rf and cellular telephone applications. the ltc1550l/ltc1551l operate from single 2.7v to 5.5v supplies and draw typical quiescent currents of 3.5ma with a 5v supply. each device includes a ttl compatible shutdown pin which drops supply current to 0.2 m a typically. the ltc1550l shutdown pin is active low (shdn), while the ltc1551l shutdown pin is active high(shdn). only four external components are required: an input bypass capacitor, two 0.1 m f charge pump capacitors and a filter capacitor at the linear regulator output. the adjustable ltc1550l/ltc1551l require two additional re-sistors to set the output voltage. the ltc1550l/ltc1551l will supply up to 20ma (depending on v cc to v out range), while maintaining guaranteed output regulation of 2.5%. both fixed voltage and adjustable ltc1550l/ltc1551lare available in 8-lead msop and so plastic packages: the adjustable ltc1550l is also available in a 16-pin ssop with the reg pin. , ltc and lt are registered trademarks of linear technology corporation. 5 m s/div 1550l/51l ta01a regulated negative voltage from a singlepositive supply low output ripple: less than 1mv p-p typ high charge pump frequency: 900khz small charge pump capacitors: 0.1 m f requires only four external capacitors fixed C 4.1v, C2.5v, C2v or adjustable output shutdown mode drops supply current to <1 m a high output current: up to 20ma (depending onv cc to v out range) output regulation: 2.5% over line, load andtemperature available in 8-lead msop, 8-lead narrow so and16-lead narrow ssop gaas fet bias generators negative supply generators battery-powered systems single supply applications v out ac coupled 2mv/div v out output noise and ripple figure 1. 2v generator with 1mv p-p noise 12 3.6v 87 reg cp out shdnv cc c1 + v out ltc1550l-2 gnd c1 C c out 10 m f 1550l/51l ta01 v out = C2v i load = 5ma c cp 0.1 m f r110k power valid c1 0.1 m f 2.2 f c in 34 65 c l 0.1 m f + + applicatio s u features typical applicatio u descriptio u downloaded from: http:///
2 ltc1550l/ltc1551l absolute m axi m u m ratings w ww u (note 1) supply voltage ...................................................... 5.5v output voltage ............................. 0.3v to (v cc C 10.5v) total voltage, v cc to cp out .......................................... 10.8v input voltage (shdn pin) ........... C 0.3v to (v cc + 0.3v) input voltage (reg pin) ............................. C 0.3v to 6v output short-circuit duration .............................. 30 sec commercial temperature range ................. 0 c to 70 c extended commercial operating temperature range (note 3) .............. C 40 c to 85 c industrial temperature range ................ C 40 c to 85 c storage temperature range ................ C 65 c to 150 c lead temperature (soldering, 10 sec)................. 300 c package/order i n for m atio n w u u order part number ltc1550lcgnltc1550lign top view gn package 16-lead plastic ssop 12 3 4 5 6 7 8 1615 14 13 12 11 10 9 nc c1 + nc v out c1 C pgndagnd nc v cc shdnreg nc adj cp out ncnc t jmax = 150 c, q ja = 150 c/w gn part marking t jmax = 150 c, q ja = 200 c/w *shdn for ltc1550l, shdn for ltc1551l *for adjustable version order part number ms8 part marking ltc1550lcms8ltc1550lcms8-2 ltc1550lcms8-2.5 ltc1550lcms8-4.1 ltc1551lcms8ltc1551lcms8-4.1 ltfq ltft ltegltgr ltfv lteh t jmax = 150 c, q ja = 135 c/w *shdn for ltc1550l, shdn for ltc1551l *for adjustable version 12 3 4 87 6 5 top view ms8 package 8-lead plastic msop reg (adj*)cp out gndc1 C shdn* v cc c1 + v out 12 3 4 87 6 5 top view reg (adj*)cp out gndc1 C shdn* v cc c1 + v out s8 package 8-lead plastic so order part number ltc1550lcs8ltc1550lcs8-2 ltc1550lcs8-2.5 ltc1550lcs8-4.1 ltc1551lcs8 ltc1551lcs8-4.1 consult factory for military grade parts and additional voltage options. 1550l1550li symbol parameter conditions min typ max units v cc supply voltage(adjustable, fixed C2v) 2.7 5.25 v (fixed C2.5v) 3.05 5.25 v (fixed C 4.1v) 4.5 5.25 v v ref reference voltage v cc = 5v, adj = gnd, v ref = Cv out 1.225 v d v ref reference voltage i out = 0ma, 2.7v v cc 5.25v 2.5 mv/v d (v cc C v out) line regulation i s supply current v cc = 5v, v shdn = v cc (ltc1550l) or gnd (ltc1551l) 3.65 7 ma v cc = 5v, v shdn = gnd (ltc1550l) or v cc (ltc1551l) 0.2 10 m a the denotes the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. v cc = 2.7v to 5.25v, c1 = c cp = 0.1 m f, c out = 10 m f, t a = 25 c unless otherwise specified. (note 3) electrical characteristics downloaded from: http:///
3 ltc1550l/ltc1551l f osc internal oscillator frequency 900 khz v ol reg output low voltage i reg = 1ma, v cc = 5v 0.1 0.8 v i reg reg sink current v reg = 0.8v, v cc = 5v 41 0 m a v ih shdn input high voltage v cc = 5v 2v v il shdn input low voltage v cc = 5v 0.8 v i in shdn input current v shdn = v cc (all ltc1550l versions) 0.1 1 m a v shdn = v cc (all ltc1551l versions) 52 0 m a t on turn-on time v cc = 5v, i out = 10ma, C1.5v v out 4.1v 15m s (ltc1550l/ltc1551l)v cc = 5v, i out = 5ma, v out = C 4.5v 15m s (ltc1550l/ltc1551l)v cc = 5v, i out = 10ma, v out = C 2v 15m s (ltc1550l-2)v cc = 5v, i out = 10ma, v out = C 2.5v 15m s (ltc1550l-2.5)v cc = 5v, i out = 10ma, v out = C 4.1v 15m s (ltc1550l-4.1/ltc1551l-4.1) v out output regulation 2.7v v cc 5.25v, 0 i out 5ma C 1.537 C 1.5 C 1.463 v (ltc1550l/ltc1551l) 2.8v v cc 5.25v, 0 i out 10ma C 1.537 C 1.5 C 1.463 v 3.5v v cc 5.25v, 0 i out 20ma C 1.537 C 1.5 C 1.463 v v out output regulation 2.7v v cc 5.25v, 0 i out 5ma C 2.05 C 2.0 C 1.95 v (ltc1550l/ltc1550l-2/ 3.1v v cc 5.25v, 0 i out 10ma C 2.05 C 2.0 C 1.95 v ltc1551l) 3.75v v cc 5.25v, 0 i out 20ma C 2.05 C 2.0 C 1.95 v v out output regulation 3.05v v cc 5.25v, 0 i out 5ma C 2.562 C 2.5 C 2.438 v (ltc1550l/ltc1550l-2.5/ 3.45v v cc 5.25v, 0 i out 10ma C 2.562 C 2.5 C 2.438 v ltc1551l) 4.1v v cc 5.25v, 0 i out 20ma C 2.562 C 2.5 C 2.438 v v out output regulation 3.45v v cc 5.25v, 0 i out 5ma C 3.075 C 3.0 C 2.925 v (ltc1550l/ltc1551l) 3.85v v cc 5.25v, 0 i out 10ma C 3.075 C 3.0 C 2.925 v 4.5v v cc 5.25v, 0 i out 20ma C 3.075 C 3.0 C 2.925 v v out output regulation 3.9v v cc 5.25v, 0 i out 5ma C 3.587 C 3.5 C 3.413 v (ltc1550l/ltc1551l) 4.2v v cc 5.25v, 0 i out 10ma C 3.587 C 3.5 C 3.413 v 4.85v v cc 5.25v, 0 i out 20ma C 3.587 C 3.5 C 3.413 v v out output regulation 4.5v v cc 5.25v, 0 i out 5ma C 4.203 C 4.1 C 3.998 v (ltc1550l/ltc1550l-4.1) 4.75v v cc 5.25v, 0 i out 10ma C 4.203 C 4.1 C 3.998 v (ltc1551l/ltc1551l-4.1) v out output regulation 4.8v v cc 5.25v, 0 i out 5ma C 4.613 C 4.5 C 4.388 v (ltc1550l/ltc1551l)) 5.1v v cc 5.25v, 0 i out 10ma C 4.613 C 4.5 C 4.388 v i sc output short-circuit current v out = 0v, v cc = 5.25v 80 200 ma v ripple output ripple voltage 1m v the denotes the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. v cc = 2.7v to 5.25v, c1 = c cp = 0.1 m f, c out = 10 m f, t a = 25 c unless otherwise specified. (note 3) electrical characteristics symbol parameter conditions min typ max units note 1: absolute maximum ratings are those values beyond which the life of a device may be impaired.note 2: all currents into device pins are positive; all currents out of device pins are negative. all voltages are referenced to ground unless otherwisespecified. all typicals are given at t a = 25 c. note 3: the ltc1550lc/ltc1551lc are guaranteed to meet specified performance from 0 c to 70 c and are designed, characterized and expected to meet these extended temperature limits, but are not tested at C40 c and 85 c. the ltc1550li is guaranteed to meet the extended temperature limits. downloaded from: http:///
4 ltc1550l/ltc1551l typical perfor m a n ce characteristics u w supply current vs temperature oscillator frequency vstemperature output voltage (v) C5 positive supply voltage (v) 6.05.6 5.2 4.8 4.4 4.0 3.6 3.2 2.8 2.4 2.0 C1 1550l/51l g03 C4 C3 C2 0 i out = 20ma i out = 10ma i out = 5ma minimum required v cc vs v out and i out temperature (?c) C55 C35 C15 5 25 45 65 85 105 125 oscillator frequency (khz) 875 925 975 1550l/51l g01 825 775 725 675 v cc = 5v v out = C4.1v temperature ( c) supply current (ma) 1550l/51l g02 v cc = 5v v out = C 4.1v C55 C35 C15 5 25 45 65 85 105 125 5.04.5 4.0 3.5 3.0 2.5 reference voltage vs v cc + |v out | start-up time vs supply voltage maximum output currentvs supply voltage load transient response(see figure 3, v cc = 5v) line transient response(see figure 3, i l = 10ma) 5v0v C 4.1v v out shdn 0.2ms/div 1550/51 g07 startup time (ltc1550l shown) 0v5v 0v power valid 0ma 1ms/div 1550/51 g08 10ma v out 5mv/div ac coupled i out 4.75v 2ms/div 1550/51 g09 v out 5mv/div ac coupled 5.25v v cc supply voltage (v) 2.25 2.75 3.25 3.75 4.25 4.75 5.25 maximum output current (ma) 1550l/51l g04 8070 60 50 40 30 20 10 0 t a = 25 c v out = C2v v out = C2.5v v out = C4.1v supply voltage (v) 2.25 2.75 3.25 3.75 4.25 4.75 5.25 start-up time (ms) 1550l/51l g05 2.52.0 1.5 1.0 0.5 0 t a = 25 c v out = C2v r l = 390 v out = C4.1v r l = 820 1.24 1.2381.236 1.234 1.232 1.230 1.228 1.226 1.224 1.222 1.220 1.218 v cc + |v out | (v) 4567891 0 4.5 5.5 6.5 7.5 8.5 9.5 reference voltage (v) 1550l/51l g06 t a = 25 c downloaded from: http:///
5 ltc1550l/ltc1551l typical perfor m a n ce characteristics u w frequency (hz) 100k noise (db v) 9080 70 60 50 40 30 20 10 0 C10 1m 10m 1550l/51l g10 frequency (khz) 1 0.01 noise ( v/ hz) 1 0.1 10 10 100 1550 /51l g11 spot noise (*see figure 1) output spectrum (see figure 3) frequency (hz) 100k noise (db v) 9080 70 60 50 40 30 20 10 0 C10 1m 10m 1550l/51l g12 v cc = 5v i l = 5ma c in = 2.2 f c out = 4.7 f c l = 0.1 f output spectrum (*see figure 1) * on first page of data sheet. spot noise (see figure 3) frequency (khz) 1 0.01 noise ( v/ hz) 1 0.1 10 10 100 1550l/51l g13 v cc = 5v i l = 5ma c in = 2.2 f c out = 4.7 f c l = 0.1 f frequency (hz) 100k noise (db v) 9080 70 60 50 40 30 20 10 0 C10 1m 10m 1550l/51l g14 v cc = 5v i l = 5ma c in 2.2 f c out = 10 f c l = 0.1 f spot noise (see figure 3) frequency (khz) 1 0.01 noise ( v/ hz) 1 0.1 10 10 100 1550l/51l g15 v cc = 5v i l = 5ma c in = 2.2 f c out = 10 f c l = 0.1 f output spectrum (see figure 3) downloaded from: http:///
6 ltc1550l/ltc1551l pi n fu n ctio n s uuu shdn: shutdown (ttl compatible). this pin is active low (shdn) for the ltc1550l and active high (shdn) for theltc1551l. when this pin is at v cc (gnd for ltc1551l), the ltc1550l operates normally. when shdn is pulledlow (shdn pulled high for ltc1551l), the ltc1550l enters shutdown mode. in shutdown, the charge pump stops, the output collapses to 0v, and the quiescent current drops typically to 0.2 m a. the shdn pin for the ltc1550l is a high impedance input and has no internalpull-up. the user must supply a resistor or current source pull-up to default the ltc1550l into normal operation. the shdn pin for the ltc1551l has an internal 5 m a typical pull-down that defaults the ltc1551l into normaloperation. v cc : power supply. v cc requires an input voltage between 2.7v and 5.25v. certain combinations of output voltageand output load current may place additional restrictions on the required input voltage. consult the electrical char- acteristics table and typical performance characteristics for guaranteed test points. the difference between the input voltage and output should not exceed 10.5v or damage to the chip may occur. v cc must be bypassed directly to pgnd (gnd for 8-pin packages) with at least a0.1 m f capacitor placed in close proximity to the chip. a 1 m f or larger low esr bypass capacitor is recommended tominimize noise and ripple at the output. a surface mount ceramic capacitor is recommended. c1 + : c1 positive input. connect a 0.1 m f capacitor between c1 + and c1 C . v out : negative voltage output. this pin must be bypassed with a 4.7 m f or larger capacitor to ensure regulator loop stability. ltc recommends at least 10 m f to achieve the specified output ripple. the output capacitor should be amoderate esr capacitor, and not a very low esr capaci- tor, as the zero in the feedback loop (formed by the esr and the output capacitor) provides phase lead to the linear regulator feedback loop. using very low esr output ca- pacitors will result in the output oscillating. a low esr 0.1 m f capacitor is recommended in parallel with the main output capacitor to minimize high frequency spikes at theoutput. the ground connection for the output capacitor should connect directly to the v cc and cp out bypass capacitors, as well as to the gnd of the ltc1550l/ltc1551l. ltc recommends a separate trace for the v out capacitor ground connection to minimize noise.c1 : c1 negative input. connect a 0.1 m f capacitor from c1 + to c1 C . gnd: ground. connect to a low impedance ground. a ground plane will help minimize regulation errors.cp out : negative charge pump output. this pin requires a 0.1 m f storage capacitor to ground. in order to achieve ripple on the output voltage of less than 1mv, the groundconnection for the cp out capacitor must tie directly to the bottom of the v cc bypass capacitor and at the gnd pin of the ltc1550l/ltc1551l. this minimizes the ac currentpath for the charge pump. reg: this is an open-drain output that pulls low when the output voltage is within 5% of the set value. it will sink 4mato ground with a 5v supply. the external circuitry must provide a pull-up or reg will not swing high. the voltage at reg may exceed v cc and can be pulled up to 6v above ground without damage. for the ltc1550l adjustablevoltage version, the reg pin is only available in the 16-lead gn package. adj (for adjustable versions): this is the feedback point for the external resistor divider string. connect a dividerstring from gnd to v out with the divided tap connected to adj. note that the resistor string needs to be connectedupside-down from a negative regulator. see the applica- tions information section for hook-up details. gn package only pgnd: power ground. connect to a low impedance ground. pgnd should be connected to the same potential asagnd. agnd: analog ground. connect to a low impedance ground. agnd should be connected to a ground plane tominimize regulation errors. nc: no internal connection. downloaded from: http:///
7 ltc1550l/ltc1551l block diagra m w C + C + s2 s3 s1 s4 c cp v cc cp out c1 + c1 C c1 clk 900khz charge pump linearregulator 1550l/51l bd v out adj reg c out 58mv 1.167v *shdn *shdn for ltc1550l, shdn for ltc1551l ** fixed output versions only comp2 **** + 1.225v applicatio n s i n for m atio n wu u u overviewthe ltc1550l/ltc1551l are switched capacitor, inverting charge pumps with internal linear post-regulators. the ltc1550l/ltc1551l provide a regulated, low ripple output at up to 20ma load current with the appropriate input voltage as output load current depends on the input/ output voltage combination. consult the graph provided in the typical performance characteristics section and the electrical characteristics table for guaranteed test points. the ltc1550l/ltc1551l are ideal for use as bias voltage generators for gaas transmitter fets in portable rf andcellular telephone applications. the ltc1550l features an active-low shutdown pin (shdn) that drops quiescent current to below 1 m a. the ltc1551l is identical to the ltc1550l, except that the shutdown pin is active-high(shdn). all members of the ltc1550l/ltc1551l family feature a 900khz charge pump frequency. the ltc1550l/ ltc1551l come standard with fixed C 4.1v, C2.5v, C2v and adjustable output voltages. the ltc1550l/ltc1551l can be configured for other fixed output voltages; contact linear technology for more information. downloaded from: http:///
8 ltc1550l/ltc1551l the ltc1550l/ltc1551l consist of two major blocks(see block diagram): an inverting charge pump and a negative linear regulator. the charge pump uses two external capacitors, c1 and c cp to generate a negative voltage at cp out . it operates by charging and discharging c1 on alternate phases of the internal 900khz clock. c1 isinitially charged to v cc through switches s1 and s3. when the internal clock changes phase, s1 and s3 open and s2and s4 close, shorting the positive side of c1 to ground. this forces the negative side of c1 below ground, and charge is transferred to c cp through s4. as this cycle repeats, the magnitude of the negative voltage approachesv cc . the 900khz internal clock frequency helps keep noise out of the 400khz to 600khz if bands commonly used byportable radio frequency systems and reduces the size of the external capacitors required. most applications can use standard 0.1 m f ceramic capacitors for c1 and c cp . increasing c1 and c cp beyond 0.1 m f has little effect on the output ripple or the output current capacity of theltc1550l/ltc1551l. the negative voltage at cp out supplies the input to the negative regulator block. this block consists of ann-channel mosfet pass device and a feedback amplifier that monitors the output voltage and compares it to the internal reference. the regulated output appears at the v out pin. the regulation loop is optimized for fast tran- sient response, enabling it to remove most of the switch-ing artifacts present at the cp out pin. output ripple is typically below 1mv p-p with output loads between 0ma and 10ma. the output voltage is set by a pair of internaldivider resistors for the fixed voltage versions. the n- channel pass device minimizes dropout, allowing the output to remain in regulation with supply voltages as low as 2.7v for an output voltage of C2v. an output capacitor of at least 4.7 m f from v out to ground is required to keep the regulator loop stable; for optimum stability and mini-mum output ripple, at least 10 m f is recommended. adjustable hook-upfor the adjustable ltc1550l/ltc1551l, the output volt- age is set with a resistor divider from gnd to v out (figure? 2). note that the internal reference and the internal feedback amplifier are set up as a positive-output regula- tor referenced to the v out pin, not as a negative regulator applicatio n s i n for m atio n wu u u figure 2. external resistor connections referenced to ground. the output resistor divider must beset to provide 1.225v at the adj pin with respect to v out . for example, a C 3v output would require a 17.4k resistor from gnd to adj, and a 12.1k resistor to v out . capacitor selectionthe ltc1550l/ltc1551l requires four external capaci- tors: an input bypass capacitor, two 0.1 m f charge pump capacitors and an output filter capacitor. the overallbehavior of the ltc1550l/ltc1551l is strongly affected by how the capacitors are used, and by how the capacitors are laid out on the printed circuit board (pcb). in particu- lar, the output capacitors value and esr have a significant effect on the output ripple and noise performance. in addition, the ground connections for the v cc bypass capacitor, the cp out capacitor and the v out bypass ca- pacitor must employ star-ground techniques at the gndpin of the ltc1550l/ltc1551l. proper capacitor selec- tion is critical for optimum performance of the ltc1550l/ ltc1551l. output ripple vs output capacitor figure 4 shows the effect of using different output capaci- tor values on the ltc1550l/ltc1551l output ripple. these curves are taken using the ltc1551l circuit in figure 3, with c in = 2.2 m f and i load = 5ma. the upper curve shows the performance with a standard tantalumcapacitor alone and the lower curve shows that of the tantalum capacitor in parallel with a 0.1 m f ceramic capaci- tor. as a general rule, larger output capacitors providelower output ripple. to keep output voltage ripple below 1mv pCp , 10 m f, or greater, in parallel with a 0.1 m f ceramic capacitor is required. to guarantee loop stability under allconditions, a minimum of 4.7 m f is required at the output. pgnd, agnd ltc1550l v out adj r1 r2 v out = C1.225v r1 + r2 r2 () 1550l/51l ? f02 downloaded from: http:///
9 ltc1550l/ltc1551l applicatio n s i n for m atio n wu u u figure 4 shows a marked decrease in peak-to-peak outputripple when a 0.1 m f ceramic capacitor is added in parallel with the tantalum output capacitor. the additional ripplewith the tantalum output capacitor alone is mostly very high order harmonics of the 900khz clock, which appear as sharp "spikes" at the output. the energy in these spikes is very small and they do not contribute to the rms output voltage, but their peak-to-peak amplitude can be several millivolts under some conditions. a 0.1 m f ceramic capaci- tor has significantly lower impedance at the spike fre-quency than a large tantalum capacitor, and eliminates most of these left-over switching spikes that the tantalum capacitor leaves behind. figure 5 and 6 show scope photos of the output of figure 4 with and without the additional ceramic capacitor at the output. a series rc or lc filter can reduce high frequency outputnoise even further. due to the high 900khz switching frequency, not much r or l is required; a ferrite bead or a relatively long pc board trace in series with 0.1 m f ceramic capacitor will usually keep the output ripple well below1mv p-p . figure 1 shows an example of an ultralow noise C 2v generator. the corresponding spectrum and spot noise plots for this circuit are shown in the typical perfor- mance characteristics section. 5 m s/div 1550l/51l f05 figure 5. output ripple with 10 m f tantalum capacitor v out ac couple 5mv/div figure 3. output ripple test circuit figure 4. output ripple vs output capacitance output capacitance ( f) 87 6 5 4 3 2 1 0 10 1550l/51l f04 output ripple (mv p-p ) 1 100 v cc = 5v t a = 25 c c in = 2.2 f without 0.1 f with 0.1 f 12 v cc 87 reg cp out shdnv cc c1 + v out ltc1551l gnd c1 C c out 10 m f 1550l/51l f03 v out C 4.1v c cp 0.1 m f c1 0.1 m f c in 2.2 f 34 65 c l 0.1 m f + + r110k 10 m s/div 1550l/51l f06 v out ac couple 2mv/div figure 6. output ripple with 10 m f tantalum capacitor paralleled with 0.1 m f ceramic capacitor downloaded from: http:///
10 ltc1550l/ltc1551l applicatio n s i n for m atio n wu u u figure 7. output ripple vs input bypass capacitance input capacitance ( f) 0.1 output ripple (mv p-p ) 87 6 5 4 3 2 1 0 1 10 100 1550l/51l f08 v cc = 5v t a = 25 c c out = 10 f output ripple vs input bypass capacitorthe input bypass capacitor (c in ) can also have a fairly significant impact on the output ripple. c in provides most of the ltc1550l/ltc1551ls supply current while it ischarging the flying capacitor (c1). inadequate input bypassing can cause the v cc supply to dip when the charge pump switches, causing the output linear regulatorto momentarily stop regulating. c in should be mounted as close to the ltc1550l/ltc1551l v cc and gnd pins as possible and its value should be significantly larger than c1. surface mount tantalum or ceramic capacitors with low esr generally provide adequate performance. figure? 7 shows the ltc1550l/ltc1551l peak-to-peak output ripple vs c in , taken using the test circuit in figure 3 with i load set at 5ma. c out is a 10 m f in parallel with a 0.1 m f ceramic capacitor.a 2.2 m f surface mount ceramic capacitor at v cc generally provides adequate output ripple performance for mostapplications. 12 4.5v v cc 5.25v 87 reg cp out shdnv cc c1 + v out ltc1550l-4.1 C 4.1v bias gnd c1 C c out 10 m f 1550l/51l ta02 c cp 0.1 m f gaas transmitter c1 0.1 m f c in 2.2 m f 34 65 c l 0.1 m f + + 4.1v output gaas fet bias generator typical applicatio n u downloaded from: http:///
11 ltc1550l/ltc1551l dimensions in inches (millimeters) unless otherwise noted. package descriptio n u information furnished by linear technology corporation is believed to be accurate and reliable. however, no responsibility is assumed for its use. linear technology corporation makes no represen-tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. gn package 16-lead plastic ssop (narrow 0.150) (ltc dwg # 05-08-1641) gn16 (ssop) 1098 * dimension does not include mold flash. mold flash shall not exceed 0.006" (0.152mm) per side ** dimension does not include interlead flash. interlead flash shall not exceed 0.010" (0.254mm) per side 12 3 4 5 6 7 8 0.229 C 0.244 (5.817 C 6.198) 0.150 C 0.157** (3.810 C 3.988) 16 15 14 13 0.189 C 0.196* (4.801 C 4.978) 12 11 10 9 0.016 C 0.050 (0.406 C 1.270) 0.015 0.004 (0.38 0.10) 45 0 C 8 typ 0.007 C 0.0098 (0.178 C 0.249) 0.053 C 0.068 (1.351 C 1.727) 0.008 C 0.012 (0.203 C 0.305) 0.004 C 0.0098 (0.102 C 0.249) 0.0250 (0.635) bsc 0.009 (0.229) ref ms8 package 8-lead plastic msop (ltc dwg # 05-08-1660) msop (ms8) 1098 * dimension does not include mold flash, protrusions or gate burrs. mold flash, protrusions or gate burrs shall not exceed 0.006" (0.152mm) per side ** dimension does not include interlead flash or protrusions. interlead flash or protrusions shall not exceed 0.006" ( 0.152mm ) per side 0.021 0.006 (0.53 0.015) 0 C 6 typ seating plane 0.007 (0.18) 0.040 0.006 (1.02 0.15) 0.012 (0.30) ref 0.006 0.004 (0.15 0.102) 0.034 0.004 (0.86 0.102) 0.0256 (0.65) bsc 12 3 4 0.193 0.006 (4.90 0.15) 8 7 6 5 0.118 0.004* (3.00 0.102) 0.118 0.004** (3.00 0.102) downloaded from: http:///
12 ltc1550l/ltc1551l 15501lf lt/tp 0300 4k ? printed in usa ? linear technology corporation 1996 typical applicatio n u related parts part number description comments lt ? 1054 switched-capacitor voltage converter with regulator 100ma switched-capacitor converter ltc1261 switched-capacitor regulated voltage inverter selectable fixed output voltages ltc1261l switched-capacitor regulated voltage inverter adjustable and fixed output voltages, up to 20ma i out , msop ltc1429 clock-synchronized switched-capacitor voltage inverter synchronizable up to 2mhz system clock ltc1514/ltc1515 step-up/step-down switched-capacitor dc/dc converters v in 2v to 10v, adjustable or fixed v out , i out to 50ma ltc1516 micropower regulated 5v charge pump dc/dc converter i out = 20ma (v in 3 2v), i out = 50ma (v in 3 3v) ltc1522 micropower regulated 5v charge pump dc/dc converter i out = 10ma (v in 3 2.7v), i out = 20ma (v in 3 3v) ltc1550/ltc1551 low noise, switched-capacitor regulated voltage inverters 900khz charge pump, 1mv p-p ripple ltc1555/ltc1556 sim power supply and level translator step-up/step-down sim power supply and level translators lt1611 1.4mhz inverting mode switching regulator C 5v at 150ma from a 5v input, 5-lead sot-23 lt1614 inverting 600khz switching regulator with low-battery detector C 5v at 200ma from a 5v input, msop ltc1754-5 micropower, regulated 5v charge pump with shutdown in sot-23 i cc = 13 m a, i out = 50ma (v in 3 3v), i out = 25ma (v in 3 2.7v) dimensions in inches (millimeters) unless otherwise noted. package descriptio n u 12 2.7v v cc 5.25v 87 reg cp out shdnv cc c1 + v out ltc1550l-2 C2v gnd c1 C c out 10 m f 1550l/51l ta03 c cp 0.1 m f gaas transmitter c1 0.1 m f c in 2.2 m f 34 65 c l 0.1 m f + + 10k reg 1mv p-p ripple, 2v output gaas fet bias generator linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear-tech.com s8 package 8-lead plastic small outline (narrow 0.150) (ltc dwg # 05-08-1610) 0.016 C 0.050 (0.406 C 1.270) 0.010 C 0.020 (0.254 C 0.508) 45 0 C 8 typ 0.008 C 0.010 (0.203 C 0.254) so8 1298 0.053 C 0.069 (1.346 C 1.752) 0.014 C 0.019 (0.355 C 0.483) typ 0.004 C 0.010 (0.101 C 0.254) 0.050 (1.270) bsc 1 2 3 4 0.150 C 0.157** (3.810 C 3.988) 8 7 6 5 0.189 C 0.197* (4.801 C 5.004) 0.228 C 0.244 (5.791 C 6.197) dimension does not include mold flash. mold flash shall not exceed 0.006" (0.152mm) per side dimension does not include interlead flash. interlead flash shall not exceed 0.010" (0.254mm) per side * ** downloaded from: http:///

▲Up To Search▲

Price & Availability of LTC1550LCGNTRPBF

	To Download LTC1550LCGNTRPBF Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .