View LT1120IS8TR_5329122.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1 lt1120 1120fd typical applicatio u applicatio s u features descriptio u micropower regulator with comparator and shutdown the lt 1120 is a combination micropower positive regu- lator and free collector comparator on a single monolithic chip. with only 40 a supply current, the lt1120 can supply over 125ma of output current. input voltage range is from 4.5v to 36v and dropout voltage is 0.6v at 125ma. dropout voltage decreases with lower load currents. also included on the chip is a class b output 2.5v reference that can either source or sink current. a shutdown pin allows logic shutdown of the output. the comparator can be used for system or battery moni- toring. for example, the comparator can be used to warn of low system voltage. frequency compensation of the comparator for amplifier applications can be obtained by adding external output capacitance. the 2.5v reference will source or sink current. this allows it to be used as a supply splitter or auxiliary output. 40 a supply current 125ma output current 2.5v reference voltage reference output sources 2ma and sinks 2ma open collector comparator sinks 10ma logic shutdown 0.2v dropout voltage thermal limiting available in 8-lead dip and so packages battery systems battery-backup system portable terminals portable instruments memory keep-alive , lt, ltc and ltm are registered trademarks of linear technology corporation. all other trademarks are the property of their respective owners. 5v regulator dropout voltage and supply current output current (ma) 0.1 1 0.01 dropout voltage (v) supply current (ma) 0.10 1.00 0.1 1 10 10 100 1000 1120 ta02 + + v in v out fb gnd shdn shutdown lt1120 4 0.001 f1m 1m 25 f 5v v in > 5.2v i q = 40 a 1120 ta01 10 f 2 1 3 5
2 lt1120 1120fd 1 2 3 4 8 7 6 5 top view gnd fb shdn v out input compout ref v in n8 package 8-lead pdip s8 package 8-lead plastic so input voltage ........................................................... 36v npn collector voltage ............................................. 36v output short-circuit duration .......................... indefinite power dissipation ............................... internally limited absolute axi u rati gs w ww u electrical characteristics package/order i for atio uu w j8 package 8-lead cerdip t jmax = 150 c, ja = 100 c/w (j) order part number lt1120cn8 lt1120cs8 lt1120in8 lt1120is8 s8 part marking the denotes the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. t j = 25 c. 1120 1120i parameter conditions min typ max units reference reference voltage 4.5v v in 36v 2.46 2.50 2.54 v line regulation 4.5v v in 36v 0.01 0.015 %/v load regulation ?ma i ref 2ma, v in = 12v 0.3 0.6 % output source current v in = 5v 2 4 ma output sink current v in = 5v 2 4 ma temperature stability 1% regulator supply current v in = 6v, i out 100 a4580 a v in = 36v, i out 100 a 75 100 a v in = 12v, i out = 125ma 11 20 ma output current (v in ?v out ) 1v, v in 6v 125 ma load regulation (v in ?v out ) 1v, v in 6v 0.2 0.5 % line regulation 6v v in 36v 0.01 0.015 %/v dropout voltage i out = 100 a 0.02 0.05 v i out = 125ma 0.4 0.65 v (note 1) consult ltc marketing for parts specified with wider operating temperature ranges. t jmax = 110 c, ja = 130 c/w (n) t jmax = 110 c, ja = 150 c/w (s) lt1120cj8 order part number obsolete packages consider the n8 and s8 packages for alternate source operating temperature range lt1120c ................................................ 0 c to 100 c lt1120i ................................................ 40 to 100 c storage temperature range ................. 65 c to 150 c top view compout input gnd fb ref v in shdn v out 8 7 6 5 3 2 1 4 h package 8-lead to-5 metal can order part number lt1120ch t jmax = 150 c, ja = 150 c/w, jc = 45 c/w
3 lt1120 1120fd parameter conditions min typ max units parameter conditions min typ max units reference reference voltage 4.5v v in 36v 2.40 2.50 2.55 v line regulation 4.5v v in 36v 0.01 0.02 %/v load regulation 2ma i ref 2ma, v in = 12v 0.4 0.8 % output source current v in = 5v 2ma output sink current v in = 5v 2ma regulator supply current v in = 6v, i out 100 a 65 95 a v in = 36v, i out 100 a 85 100 a v in = 12v, i out = 125ma 11 20 ma output current (v in ?v out ) 1v, v in 6v 125 ma load regulation (v in ?v out ) 1v, v in 6v 1% line regulation 6v v in 36v 0.02 %/v dropout voltage i out = 100 a 0.06 v i out = 125ma 0.85 v feedback sense voltage v in = 12v 2.38 2.5 2.57 v feedback bias current 50 na minimum load current v in = 36v 50 a short-circuit current v in = 36v 300 400 ma electrical characteristics the denotes the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. t j = 25 c. the denotes the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. feedback sense voltage v in = 12v 2.44 2.5 2.56 v shutdown pin voltage normal 0.4 v v out 0.5v shutdown 2.2 1.4 v shutdown pin current v in = 1.4v 25 a feedback bias current 15 40 na minimum load current v in = 36v 15 a short-circuit current v in = 36v 300 400 ma comparator offset voltage v in = 36v 37mv bias current v in = 36v (note 2) 15 40 na gain v out = 29v, r l = 20k 2000 10000 v/v power supply rejection 4.5v v s 36v 80 96 db output sink current v in = 4.5v 10 18 ma saturation voltage i out = 1ma 0.4 0.6 v input voltage range 0v in ?1 v response time 5 s leakage current 2 a
4 lt1120 1120fd parameter conditions min typ max units electrical characteristics note 1: stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. exposure to any absolute maximum rating condition for extended periods may affect device reliability and lifetime. typical perfor a ce characteristics uw regulator output current (ma) 0.1 1 0.01 supply current (ma) 1 100 10 100 1000 1120 g02 0.1 10 t j = 55 c to 125 c temperature ( c) 50 10 30 70 110 150 short-circuit current (ma) 1120 g03 350 300 250 200 150 100 50 0 current limit tied to ground output current (ma) output voltage change (%) 0.3 0.2 0.1 0 0.1 0.2 0.3 0.1 10 100 1000 1120 g01 1 preload = 100 a t j = 125 c t j = 25 c t j = 55 c regulator load regulation supply current regulator short-circuit current dropout voltage temperature ( c) 70 80 90 100 110 120 130 140 150 minimum load current ( a) 100 10 1 1120 g05 ripple frequency (hz) ripple rejection (db) 70 65 60 55 50 45 40 35 30 10 1k 10k 100k 1120 g06 100 i out = 100ma i out = 1ma v in = 10vdc, 1v p? v out = 5v c out = 10 f i out = 10ma regulator minimum load current regulator ripple rejection regulator output current (ma) 0.1 1 0.01 regulator input-output differential (v) 0.1 1 10 100 1000 1120 g04 v out = 100mv comparator offset voltage 10 mv bias current v in = 36v (note 2) 15 60 na gain v out = 29v, r l = 20k 1000 v/v output sink current v in = 4.5v (note 3) 510 ma leakage current v in = 36v 8 a the denotes the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. note 2: t a > 85 c, i bias maximum is 100na. note 3: for t a ?0 c output current sink drops to 2.5ma.
5 lt1120 1120fd typical perfor a ce characteristics uw regulator input-output differential (v) 1 5 10 15 20 25 supply current (ma) 10 1 0.1 0.01 1120 g07 i out = 100ma i out = 1ma v out = 5v t j = ?5 c to 125 c i out = 10ma regulator input-output differential (v) 1 0.1 0.2 0.3 0.4 0.5 0.6 supply current (ma) 10 1 0.1 0.01 1120 g08 i out = 100ma i out = 1ma t j = 55 c to 125 c i out = 10ma reference output current (ma) ?.5 ?.0 ?.5 0 0.5 1.0 1.5 reference voltage change (mv) 1120 g09 4 3 2 1 0 ? ? ? ? time (ms) 0 20 40 60 80 100 120 140 160 180 output current (ma) output voltage change (%) 1120 g12 0.1 0 0.1 0 50 v in = 15v v out = 5v regulator output current (ma) feedback current (na) 40 35 30 25 20 15 10 5 0 0.1 10 100 1000 1120 g11 1 t j = 125 c t j = 25 c t j = 55 c supply current supply current at dropout reference regulation feedback pin current regulator thermal regulation lt1120 turn-on characteristic input voltage (v) 012345678 output voltage (v) 1120 g13 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 0 v out = 5v r l = 50 r l = 500 no load
6 lt1120 1120fd gnd (pin 1): ground. fb (pin 2): feedback. this is the feedback point of the regulator. when operating, it is nominally at 2.5v. opti- mum source resistance is 200k to 500k. the feedback pin should not be driven below ground or more positive than 5v. shdn (pin 3): shutdown. a logic 1 shuts off the main regulator. caution: noise or leakage into the shutdown pin can affect output voltage. v out (pin 4): regulator output. main output, requires a 10 f output capacitor. can be shorted to v in or ground without damaging the device. pi fu ctio s uuu v in (pin 5): input supply. bypass with a 10 f capacitor. must always be more positive than ground. ref (pin 6): reference. 2.5v can source or sink current. may be shorted to ground or up to 5v. voltages in excess of 5v can damage the device. compout (pin 7): comparator output. open collector npn output. may be connected to any voltage from ground to 36v more positive than ground (operates above v in ). short-circuit protected. input (pin 8): comparator input. inverting comparator input. block diagra w 50k 1120 bd + ref 2.5v 4 6 v out compout 60k 5 v in 2fb 3 shdn gnd ref 8 input + 1 7 applicatio s i for atio wu u u the lt1120 is especially suited for micropower system applications. for example, the comparator section of the lt1120 may be used as a battery checker to provide an indication of low battery. another type of system applica- tion for the lt1120 would be to generate the equivalent of split supplies off of a single power input. the regulator section provides regulated output voltage and the refer- ence, which can both source and sink current, is then an artificial system ground providing a split supply for the system. for many applications the comparator can be frequency compensated to operate as an amplifier. compensation values for various gains are given in the data sheet. the comparator gain is purposely low to make it easier to frequency compensate as an amplifier. the npn output is capable of sinking 10ma and can drive loads connected to voltages in excess of the positive power supply. this is useful for driving switches or linear regulators off of a higher input voltage.
7 lt1120 1120fd applicatio s i for atio wu u u reference internal to the lt1120 is a 2.5v trimmed class b output reference. the reference was designed to be able to source or sink current so it could be used in supply splitting applications as well as a general purpose reference for external circuitry. the design of the reference allows it to source typically 4ma or 5ma and sink 2ma. the available source and sink current decreases as temperature in- creases. it is sometimes desirable to decrease the ac output impedance by placing an output capacitor on them. the reference in the lt1120 becomes unstable with large capacitive loads placed directly on it. when using an output capacitor, about 20 should be used to isolate the capacitor from the reference pin. this 20 resistor can be placed directly in series with the capacitor or alternatively the reference line can have 20 placed in series with it and then a capacitor to ground. this is shown in figure 1. other than placing large capacitive loads on the reference, no other precautions are necessary and the reference is stable with nominal stray capacitances. overload protection the main regulator in the lt1120 is current limited at approximately 250ma. the current limit is stable with both input voltage and temperature. like most other ic regulators, a minimum load is required on the output of the lt1120 to maintain regulation. for most standard regulators this is normally specified at 5ma. of course, for a micropower regulator this would be a tremendously large current. the output must be large enough to absorb all the leakage current of the pass transistor at the maximum operating temperature. it also effects the transient response; low output currents have long recovery times from load transients. at high operat- ing temperatures the minimum load current increases and having too low of a load current may cause the output to go unregulated. devices are tested for minimum load current at high temperature. the output voltage setting resistors to the feedback terminal can usually be used to provide the minimum load current. frequency compensation the lt1120 is frequency compensated by a dominant pole on the output. an output capacitor of 10 f is usually large enough to provide good stability. increasing the output capacitor above 10 f further improves stability. in order to ensure stability, a feedback capacitor is needed between the output pin and the feedback pin. this is because stray capacitance can form another pole with the large value of feedback resistors used with the lt1120. also, a feedback capacitor minimizes noise pickup and improves ripple rejection. with the large dynamic operating range of the output current, 10000:1, frequency response changes widely. low ac impedance capacitors are needed to insure stabil- ity. while solid tantalum are best, aluminum electrolytics can be used but larger capacitor values may be needed. + ref output or 20 10 f 1120 f01 6 + ref output 20 10 f 6 figure 1. bypassing reference
8 lt1120 1120fd typical applicatio s u regulator with output voltage monitor + v in v out fb gnd ref lt1120 4 0.001 f 98k 500k 5v logic logic output 100k 2k 10 f v out v out 5v 1120 ta03 2 input 8 1 6 5 7 + logic output goes low when v out drops by 100mv pin 7 logic output compensating the comparator as an op amp 1a low dropout regulator + v out fb gnd lt1120 4 0.001 f 100k mje2955 10k* 2.2k v in * 100k 150 * 220 f ? v out 5v 1120 ta05 2 1 v in 5 * for current limit 1.5a ? must have low esr. several 100 f capacitors can be paralleled. c1 50 a at av = 100, slew rate = +0.05v/ s 6v/ s + r2 6 8 7 r1 1m c2 1120 ta04 av r1 c1 c2 r2 133 0.1 f 0.001 f 10 100 0.047 f 100k 100 10k 0.002 f 10k
9 lt1120 1120fd typical applicatio s u + v in v out fb gnd lt1120 4 0.001 f1m 1m 10 f logic input 5v out nc 2n3904* v in > 5.2v i q = 40 a 1120 ta09 2 1 5 * transistor used because of low leakage characteristics. to turn off the output of the lt1120 force fb (pin 2) > 2.5v. 5v regulator with feedback shutdown battery-backup regulator + v in v out fb gnd lt1120 4 0.001 f1m 50k 1m 10 f v out 5v battery input main power input 1120 ta08 2 1 5 v in v out fb gnd lt1120 5 1 4 2 internal parasitic diodes of lt1120 v out v in 5v regulator regulator with improved transient response + + v in v out fb gnd lt1120 4 0.001 f1m 1m 25 f 5v v in > 5.2v i q = 40 a 1120 ta06 10 f 2 1 5 + v in v out fb gnd lt1120 4 0.001 f 0.001 f 1m 1m 22k 25 f 5v v in > 5.2v 1120 ta07 2 1 5
10 lt1120 1120fd sche atic diagra w w q35 8 q61 q62 q63 q32 q34 q60 q13 q22 q19 q9 q6 q11 q8 q59 input 3 shdn 1 gnd 1120 schem 4 v out 6 ref 2 fb 5 v in 7 compout r17 100 r10 75k r34 60k r38 20k r14 15k r15 80k r19 40k r8 40k 281k 15k r27 15k r26 15k r29 5 r32 2k r28 2k q30 q21 q24 q31 r11 15k q23 q20 q26 q25 r35 42k r4 42k q14 q38 q39 q27 c2 25pf q28 r18 15k q40 q41 q33 r16 6k c3 10pf c5 100pf r7 6.8k c1 10pf q29 q36 q16 q15 q18 q17 r6 3k r3 50k r37 110.8k r2 50k r36 60k q5 r1 25 q2 q10 q12 q7 q37 q45 q48 q46 q47 r8 100k r30 2k q42 q52 q54 r22 30k q51 q58 q55 q43 q44 r24 390k r23 30k 125k 125k 100pf r31 10 100pf c6 100pf q49 q56 r33 47k 138.3k
11 lt1120 1120fd n8 package 8-lead pdip (narrow .300 inch) (reference ltc dwg # 05-08-1510) j8 package 8-lead cerdip (narrow .300 inch, hermetic) (reference ltc dwg # 05-08-1110) h package 8-lead to-5 metal can (.230 inch pcd) (reference ltc dwg # 05-08-1321) package descriptio u n8 1002 .065 (1.651) typ .045 ?.065 (1.143 ?1.651) .130 .005 (3.302 0.127) .020 (0.508) min .018 .003 (0.457 0.076) .120 (3.048) min 12 3 4 87 6 5 .255 .015* (6.477 0.381) .400* (10.160) max .008 ?.015 (0.203 ?0.381) .300 ?.325 (7.620 ?8.255) .325 +.035 ?015 +0.889 0.381 8.255 () note: 1. dimensions are inches millimeters *these dimensions do not include mold flash or protrusions. mold flash or protrusions shall not exceed .010 inch (0.254mm) .100 (2.54) bsc j8 0801 .014 ?.026 (0.360 ?0.660) .200 (5.080) max .015 ?.060 (0.381 ?1.524) .125 3.175 min .100 (2.54) bsc .300 bsc (7.62 bsc) .008 ?.018 (0.203 ?0.457) 0 ?15 .005 (0.127) min .405 (10.287) max .220 ?.310 (5.588 ?7.874) 12 3 4 87 65 .025 (0.635) rad typ .045 ?.068 (1.143 ?1.650) full lead option .023 ?.045 (0.584 ?1.143) half lead option corner leads option (4 plcs) .045 ?.065 (1.143 ?1.651) note: lead dimensions apply to solder dip/plate or tin plate leads 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. .050 (1.270) max .016 ?.021** (0.406 ?0.533) .010 ?.045* (0.254 ?1.143) seating plane .040 (1.016) max .165 ?.185 (4.191 ?4.699) gauge plane reference plane .500 ?.750 (12.700 ?19.050) .305 ?.335 (7.747 ?8.509) .335 ?.370 (8.509 ?9.398) dia .230 (5.842) typ .027 ?.045 (0.686 ?1.143) .028 ?.034 (0.711 ?0.864) .110 ?.160 (2.794 ?4.064) insulating standoff 45 typ h8 (to-5) 0.230 pcd 0801 lead diameter is uncontrolled between the reference plane and the seating plane for solder dip lead finish, lead diameter is .016 ?.024 (0.406 ?0.610) * ** pin 1 obsolete packages
12 lt1120 1120fd s8 package 8-lead plastic small outline (narrow .150 inch) (reference ltc dwg # 05-08-1610) linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com ? linear technology corporation 1989 lt 0907 rev d ?printed in usa typical applicatio u current limited 1a regulator + v out fb gnd lt1120 4 0.22 f 100k mje2955 2.2k 0.5 * v in 100k 270 220 f ? v out 5v at 1a 1120 ta10 2 1 v in 5 2n3906* * sets current limit but increases dropout voltage by 0.5v ? must have low esr. several 100 f capacitors can be paralleled related parts part number description comments lt1121 150ma micropower low dropout regulator 0.4v dropout voltage, includes shutdown, sot-223, s8 packages lt1521 300ma mircopower low dropout regulator lowest i q low dropout regulator, sot-223, s8, ms8 packages lt1761 100ma micropower low noise, low dropout regulator sot-23, 20 v rms noise, 20 a i q, thinsot package .016 ?.050 (0.406 ?1.270) .010 ?.020 (0.254 ?0.508) 45 0 ?8 typ .008 ?.010 (0.203 ?0.254) so8 0303 .053 ?.069 (1.346 ?1.752) .014 ?.019 (0.355 ?0.483) typ .004 ?.010 (0.101 ?0.254) .050 (1.270) bsc 1 2 3 4 .150 ?.157 (3.810 ?3.988) note 3 8 7 6 5 .189 ?.197 (4.801 ?5.004) note 3 .228 ?.244 (5.791 ?6.197) .245 min .160 .005 recommended solder pad layout .045 .005 .050 bsc .030 .005 typ inches (millimeters) note: 1. dimensions in 2. drawing not to scale 3. these dimensions do not include mold flash or protrusions. mold flash or protrusions shall not exceed .006" (0.15mm) package descriptio u

▲Up To Search▲

Price & Availability of LT1120IS8TR

	To Download LT1120IS8TR Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .