LT1431 Programmable Reference Features Description n n n n n The LT®1431 is an adjustable shunt voltage regulator with 100mA sink capability, 0.4% initial reference voltage tolerance and 0.3% typical temperature stability. On-chip divider resistors allow the LT1431 to be configured as a 5V shunt regulator, with 1% initial voltage tolerance and requiring no additional external components. By adding two external resistors, the output voltage may be set to any value between 2.5V and 36V. The nominal internal current limit of 100mA may be decreased by including one external resistor. n Guaranteed 0.4% Initial Voltage Tolerance 0.1Ω Typical Dynamic Output Impedance Fast Turn-On Sink Current Capability, 1mA to 100mA Low Reference Pin Current Available in J8, N8, S8 or 3-Lead TO-92 Z Packages Applications Linear Regulators Adjustable Power Supplies n Switching Power Supplies n n L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. A simplified 3-pin version, the LT1431CZ/LT1431IZ, is available for applications as an adjustable reference and is pin compatible with the TL431. Typical Application Isolated 5V Regulator + 5V + VIN SWITCHING REGULATOR VREF vs Temperature 2.5025 2.5000 – 2.4975 RTOP V+ COMP VREF (V) 5V COLL 2.4950 2.4925 REF + 2.4900 gm = 4mA/V 2.4875 –50 –25 – RMID 50 25 75 0 TEMPERATURE (°C) 100 125 LT1431 TA01b 2.5V LT1431 GND-S GND-F LT1431 TA01 1431fd LT1431 Absolute Maximum Ratings (Note 1) V+, VCOLLECTOR..........................................................36V VCOMP, RTOP, RMID, VREF..............................................6V GND-F to GND-S.......................................................0.7V Ambient Temperature Range LT1431M............................................. –55°C to 125°C LT1431I.................................................–40°C to 85°C LT1431C...................................................0°C TO 70°C Junction Temperature Range LT1431M............................................. –55°C to 150°C LT1431I............................................... –40°C to 100°C LT1431C.................................................. 0°C to 100°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec)................... 300°C Pin Configuration TOP VIEW 8 REF COLLECTOR 1 3 6 GND-F RTOP 4 5 GND-S V 8 REF COLLECTOR 1 7 RMID COMP 2 + TOP VIEW 7 RMID COMP 2 + 3 6 GND-F RTOP 4 5 GND-S V J8 PACKAGE 8-LEAD CERDIP TJMAX = 150°C, θJA = 100°C/W N8 PACKAGE 8-LEAD PLASTIC DIP TJMAX = 100°C, θJA = 130°C/W TOP VIEW BOTTOM VIEW COLLECTOR 1 8 REF COMP 2 7 RMID V+ 3 6 GND-F RTOP 4 5 GND-S REF ANODE CATHODE Z PACKAGE 3-LEAD TO-92 PLASTIC TJMAX = 100°C, θJA = 150°C/W S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 100°C, θJA = 170°C/W Order Information LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT1431CN8#PBF LT1431CN8#TRPBF LT1431 CN8 8-Lead Plastic DIP 0°C to 70°C LT1431IN8#PBF LT1431IN8#TRPBF LT1431 IN8 8-Lead Plastic DIP –40°C to 85°C LT1431CS8#PBF LT1431CS8#TRPBF LT1431 8-Lead Plastic SO 0°C to 70°C LT1431IS8#PBF LT1431IS8#TRPBF LT1431I 8-Lead Plastic SO –40°C to 85°C LT1431MJ8#PBF LT1431MJ8#TRPBF LT1431 MJ8 8-Lead CERDIP –55°C to 125°C LT1431CZ#PBF LT1431CZ#TRPBF LT1431 CZ 3-Lead TO-92 Plastic 0°C to 70°C LT1431IZ#PBF LT1431IZ#TRPBF LT1431 IZ 3-Lead TO-92 Plastic –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ 1431fd LT1431 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. IK = 10mA unless otherwise specified (Note 2) LT1431I, LT1431M SYMBOL PARAMETER CONDITIONS VREF Reference Voltage VKA = 5V, IK = 2mA, (Note 3) MIN l ∆VREF/∆T Reference Drift TYP MAX LT1431C MIN TYP MAX UNITS 2.490 2.500 2.510 2.490 2.500 2.510 2.465 2.535 2.480 2.520 V V VKA = 5V, IK = 2mA l 50 ∆VREF/∆VKA Voltage Ratio, Reference to Cathode (Open-Loop Gain) IK = 2mA, VKA = 3V to 36V l 0.2 0.5 0.2 0.5 mV/V |IREF| VKA = 5V, TA = 25°C 0.2 1.0 1.5 0.2 1.0 1.2 µA µA 0.6 1.0 0.6 1.0 mA Reference Input Current l IMIN Minimum Operating Current VKA = VREF to 36V |IOFF| Off-State Cathode Current VKA = 36V, VREF = 0V |ILEAK| Dynamic Impedance VKA = VREF, IK = 1mA to 100mA, f ≤ 1kHz ILIM Collector Current Limit VKA = VREF + 50mV 5V Reference Output Internal Divider Used, IK = 2mA 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. Note 2: VKA is the cathode voltage of the LT1431CZ/IZ and corresponds to V+ of the LT1431CN8/IN8/CS8/IS8. IK is the cathode current of the ppm/°C l 1 15 1 2 µA µA l 1 5 1 2 µA µA Off-State Collector Leakage Current VCOLL = 36V, V+ = 5V, VREF = 2.4V |ZKA| 30 0.2 l 80 360 100 0.2 Ω 260 mA 4.950 5.000 5.050 4.950 5.000 5.050 V LT1431CZ/IZ and corresponds to I(V+) + I COLLECTOR of the LT1431CN8/ IN8/CS8/IS8. Note 3: The LT1431 has bias current cancellation which is effective only for VKA ≥ 3V. A slight (≈2mV) shift in reference voltage occurs when VKA drops below 3V. For this reason, these tests are not performed at VKA = VREF. 1431fd LT1431 Typical Performance Characteristics 2.5V Reference IK vs VKA 1000 2.505 VREF and IREF vs V + 3.5 2.505 VREF and IREF vs V + 3.5 2.504 3.0 800 2.503 2.5 2.503 2.5 2.502 2.0 2.502 2.0 2.501 1.5 2.501 1.5 IMIN IK (µA) VREF (V) 600 500 400 2.499 300 2.498 200 100 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VKA (V) 0 VREF 2.500 1.0 0.5 IREF 2.498 2.497 –0.5 2.497 2.496 –1.0 2.496 –1.5 2.495 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 + V (V) 2.495 2.4925 –0.33 2.4900 –0.66 50 25 75 0 TEMPERATURE (°C) –1.00 125 100 0.875 105 1 OUTPUT LT1431 5 0.625 0.20 0.500 –50 –25 100 6 50 25 75 0 TEMPERATURE (°C) OUTPUT HIGH-TO-LOW 30 OUTPUT LOW-TO-HIGH 15 0 50 150 100 OVERDRIVE (mV) 200 PHASE 20 LT1431 TPC07 –20 100 135 109 –45 40 –90 0 250 1010 0 60 –135 1k 10k 100k FREQUENCY (Hz) 1M –180 10M LT1431 TPC08 125 180 45 80 0 –50 –25 LT1431 TPC05 90 AV ICOLL = 20mA ICOLL = 10mA 50 25 75 0 TEMPERATURE (°C) 100 125 LT1431 TPC06 Transconductance and Phase vs Frequency (REF to COLL) 180 135 PHASE 108 107 90 45 gm PHASE (DEG) 75 60 45 100 PHASE (DEG) 90 ICOLL = 50mA 0.40 120 REF-TO-COLL 1k LOAD AV (dB) VREF ± OVERDRIVE ICOLL = 100mA 0.60 0.750 Ω PROPAGATION DELAY (µs) 120 1.00 0.80 140 135 0 0.7 AT 25°C RLIM + 3.6 Voltage Gain and Phase vs Frequency 150 –1.5 COLLECTOR VSAT vs Temperature vs Current 1.000 LT1431 TPC04 Propagation Delay vs Overdrive 5V 1k 3 12 16 20 24 28 32 36 40 V+ (V) 8 LT1431 TPC03 VSAT (V) 0 ILIMIT (NORMALIZED) IREF IREF (µA) VREF (V) 0.33 2.4875 –50 –25 4 1.20 1.125 0.66 2.4975 2.4950 0 1.250 ILIMIT = VREF 2.5000 0 –0.5 –1.0 ILIMIT vs Temperature with External Resistor 1.00 0.5 IREF LT1431 TPC02 VREF and IREF vs Temperature 1.0 VREF 2.499 0 LT1431 TPC01 2.5025 2.500 REF-TO-COLL gm (µ ) 700 VREF (V) 3.0 IREF (µA) 2.504 IREF (µA) 900 106 0 105 –45 104 –90 103 –135 102 100 1k 10k 100k FREQUENCY (Hz) 1M –180 10M LT1431 TPC09 1431fd LT1431 Typical Performance Characteristics Transconductance and Phase vs Frequency (Ref to Comp) PHASE gm 1.4 0 1.2 –20 103 –60 –80 3 s102 PHASE (DEG) –40 10k 100k FREQUENCY (Hz) 1M 2.5 2.0 0.8 0.6 0.5 1k 10k FREQUENCY (Hz) LT1431 TPC10 ICOMP vs VCOMP vs VREF LT1431 TPC11 100 125 LT1431 TPC12 0.1Hz to 10Hz Noise NOISE VOLTAGE (50µV/DIV) NOISE (nV/√Hz) VREF = 5V 400 ICOMP (µA) 50 25 75 0 TEMPERATURE (°C) 1000 500 VREF = 4V 300 VREF = 3V 200 500 VREF = 2.53V 100 0 0 –50 –25 100k Noise vs Frequency 600 ICOLL = 10mA 1.0 0 100 –140 10M ICOLL = 100mA 1.5 0.2 –120 1k IK ≤ 100mA 0.4 –100 0.1 100 3.0 1.0 ZKA (Ω) Ω REF-TO-COLL gm (µ ) 3 s103 VCOMP vs Temperature vs ICOLL Dynamic Impedance vs Frequency 20 VCOMP (V) 104 0 0.5 1.0 1.5 2.0 VCOMP (V) 2.5 3.0 3.5 LT1431 TPC13 0 1 10 100 1k FREQUENCY (Hz) 10k 100k LT1431 G14 0 1 4 3 2 TIME (MINUTES) 5 6 LT1431 TPC15 1431fd LT1431 Pin Functions COLL (Pin 1): Open collector of the output transistor. The maximum pin voltage is 36V. The saturation voltage at 100mA is approximately 1V. RMID (Pin 7): Middle of the on-chip resistive divider string between RTOP and GND-S. The pin is tied to REF for selfcontained 5V operation. It may be left open if unused. COMP (Pin 2): Base of the driver for the output transistor. This pin allows additional compensation for complex feedback systems and shutdown of the regulator. It must be left open if unused. REF (Pin 8): Control pin of the shunt regulator with a 2.5V threshold. If V+ > 3V, input bias current cancellation reduces IB to 0.2µA typical. V + (Pin 3): Bias voltage for the entire shunt regulator. The maximum input voltage is 36V and the minimum to operate is equal to VREF (2.5V). The quiescent current is typically 0.6mA. RTOP (Pin 4): Top of the on-chip 5k-5k resistive divider that guarantees 1% accuracy of operation as a 5V shunt regulator with no external trim. The pin is tied to COLL for self-contained 5V operation. It may be left open if unused. See note on parasitic diodes below. GND-S (Pin 5): Ground reference for the on-chip resistive divider and shunt regulator circuitry except for the output transistor. This pin allows external current limit of the output transistor with one resistor between GND-F (force) and GND-S (sense). COMP, RTOP, RMID, and REF have static discharge protection circuits that must not be activated on a continuous basis. Therefore, the absolute maximum DC voltage on these pins is 6V, well beyond the normal operating conditions. As with all bipolar ICs, the LT1431 contains parasitic diodes which must not be forward biased or else anomalous behavior will result. Pin conditions to be avoided are RTOP below RMID in voltage and any pin below GND-F in voltage (except for GND-S). The following pin definitions apply to the Z package. CATHODE: Corresponds to COLL and V+ tied together. ANODE: Corresponds to GND-S and GND-F tied together. REF: Corresponds to REF. GND-F (Pin 6): Emitter of the output transistor and substrate connection for the die. Block Diagram RTOP V 4 + 3 COMP 2 COLLECTOR 1 5k REF RMID 8 + 7 – 5k gm = 4mA/V 2.5V 5 GND-SENSE 6 LT1431 BD GND-FORCE 1431fd LT1431 Applications Information Frequency Compensation response of the LT1431 with dominant pole or pole-zero compensation. This can be accomplished with a capacitor or series resistor and capacitor between COLL and COMP. As a shunt regulator, the LT1431 is stable for all capacitive loads on the COLL pin. Capacitive loading between 0.01µF and 18µF causes reduced phase margin with some ringing under transient conditions. Output capacitors should not be used arbitrarily because output noise is not necessarily reduced. The compensation schemes mentioned above use voltage feedback to stabilize the circuits. There must be voltage gain at the COLL pin for them to be effective, so the COLL pin must see a reasonable AC impedance. Capacitive loading of the COLL pin reduces the AC impedance, voltage gain, and frequency response, thereby decreasing the effectiveness of the compensation schemes, but also decreasing their necessity. Excess capacitance on the REF pin can introduce enough phase shift to induce oscillation when configured as a reference >2.5V. This can be compensated with capacitance between COLL and REF (phase lead). More complicated feedback loops may require shaping of the frequency Typical Applications 2.5V Reference 3-Pin Package VIN 2.5V Reference 8-Pin Package RL 2.5V GND-S ANODE RL 5V + ∆ RTOP GND-S COLL LT1431 LT1431 RMID GND-F GND-S GND-F REF LT1431 TA04 Programmable Reference with Adjustable Current Limit Increasing 5V Reference V+ RTOP REF COLL LT1431 TA03 LT1431 TA02 VIN 5V V+ COLL LT1431 RL VIN 2.5V V+ REF LT1431Z R RL VIN CATHODE 5V Reference RL VIN V+ REF COLL LT1431 RMID GND-F ∆ = R • (0.5mA) ±25% PROCESS TOLERANCE ∆ ≤ 500mV R1 REF R2 GND-F GND-S LT1431 TA05 ( ) VOUT = 1 + R1 VREF R2 RLIM ILIMIT = 0.7 AT 25°C RLIM + 3.6 LT1431 TA06 1431fd LT1431 Typical Applications PNP Low Dropout 5V Regulator* VIN 0.1µF 20Ω** 2W 1k 47Ω MJE2955 2N2219 0.015µF 150Ω 3 4 2 COMP V+ RTOP 1 COLL LT1431 GND-S 5 REF RMID 8 7 GND-F 6 + MEASURED DROPOUT VOLTAGE 420mV AT 4A 190mV AT 2A 95mV AT 1A 60mV AT 0.5A 5V 330µF LT1431 TA07 *NO SHORT-CIRCUIT PROTECTION **MAY BE INCREASED AT LOWER WATTAGE FOR LOWER OUTPUT CURRENTS FET Low Dropout 5V Regulator with Current Limit 12V VIN ≥ 5.2V MTP50N05EL MTM25N05L + D 47µF 0.002Ω* S – G 1.5k 7 2 + 3 + 4 5V, 2.5A 47µF LT1006 LT1006 5 1N4148 Measured Dropout Voltages ILOAD 2A 1A 0.5A MTP50N05EL 47mV 22mV 11.5mV MTM25N05L 145mV 73mV 37mV 3 4 1 COLL V+ RTOP GND-S 5 LT1431 REF RMID 6 8 7 GND-F 6 LT1431 • TA08 *1.5" #23 SOLID COPPER WIRE ~0.002Ω m 3A LIMIT 1431fd LT1431 Typical Applications 12V to 5V Buck Converter with Foldback Current Limit* Buck Converter Efficiency 80 PULSE ENGINEERING #PE-51515 VOUT LT1089 HI-SIDE SWITCH LOGIC IN 3 4 100Ω 0.5W MBR735 GND 5k 1500pF 2 COMP V+ RTOP GND-S 5 VIN = 12V 60 VIN = 15V 50 40 1 COLL LT1431 VIN = 9V 70 EFFICIENCY (%) VIN VIN REF RMID 8 30 7 0 1 2 4 3 5 6 ILOAD (A) GND-F 6 + *CONTACT LTC FOR HIGH EFFICIENCY SWITCHING REGULATORS 7 8 LT1431 TA10 5V, 7A 3300µF LT1431 TA09 Isolated 5V to ± 15V Flyback Converter COILTRONICS CTX02-11934 6, 7 4.5V TO 5.5V 0.47µF VIN LT1172 OR LT1072 GND VOUT C* 210µF LT1172 LT1072 30mVP-P 40mVP-P 6mVP-P 8mVP-P 15k L* • + 2 10 100µF + 100µF *L BELL INDUSTRIES J.W. MILLER DIVISION 9310-36 10µH, 450mA • VC + 15V, 70mA C* 1.5k 4N36 0.68µF LT1431 TA12 MUR105 1 MEASURED EFFICIENCY LT1172 67.8% AT 2.2WOUT LT1072 68.6% AT 2.2WOUT LT1071 61.1% AT 4.4WOUT + –15V, 70mA + • 4, 5 50µF C* MUR105 3k MUR105 + 9 Fully Loaded Output Ripple vs Filtering 2.4k 0.1µF 1 20k 2 3 V+ 8 REF COLL LT1431 COMP GND-S 5 13.3k 2.7k GND-F 6 LT1431 TA11 1431fd LT1431 Typical Applications 5V Power Supply Monitor with ± 500mV Window and 50mV Hysteresis Transfer Function 6 1k 6k* 1k 4k* V+ V+ COLL REF LT1431 GND-S 4 VOUT 1N4148 5 “HIGH” FOR OVER VOLTAGE OR UNDER VOLTAGE COLL REF LT1431 5k GND-F GND-S 2 5k GND-F 1 10Ω** *DETERMINES WINDOW SIZE V = (R – 5k)(0.5mA) **SETS HYSTERESIS 10Ω** 3 0 0 1 2 LT1431 TA13 3 VIN 4 5 6 LT1431 TA14 High Efficiency Buck Converter E = 85% to 89% 1 + D1 BAT85 C1 220µF 35V BOLD LINES INDICATE HIGH CURRENT PATHS *1% FILM RESISTORS C1: NICHICON UPL1V221MPH C3, C4, C5: WIMA MKS-2 C6: NICHICON UPL1C471MPH6 D1, D2: PHILIPS BAT85 D3: MOTOROLA MBR330 L1: COILTRONICS CTX50-3-MP 5 VIN 4 VSW LT1170 2 FB GND VC R1 470k + C2 4.7µF 35V TANT 3 D4 BAT85 C5 0.047µF 1 R2 1k C3 0.1µF C4 0.033µF D3 L1 MBR330 50µH 3A 0.12Ω ESR D2 BAT85 OFF 1 RUN = 0 SHUTDOWN > 3V R3 10k RTN R4 100Ω 2 5V 2.5A 1 COMP Q3 2N3904 R5 680Ω C6 470µF 16V R6* 23.7k Q2 2N3904 Q1 VN2222LL + VIN R8* 24.9k COLL 3 + 8 V REF LT1431CN8 4 7 RTOP RMID GND-S GND-F 5 6 R7* 24.9k 2 NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTANCES ARE IN Ω, 0.25W, 5% 2. ALL CAPACITANCES ARE IN µF, 50V, 10% 3. SHUTDOWN LOGIC STATE MUST BE DEFINED BY A LOGIC GATE OR BY TYING TO GND 1431 TA15 1431fd 10 LT1431 Schematic Diagram Q5 R1 35k 4X R2 35k Q2 Q1 Q7 3 Q13 V + Q17 3X Q10 Q11 Q3 Q12 Q6 2X 8 REF Q9 Q14 C1 22pF R11 11k C2 65pF R15 5k R17 1.5k R13 6.5k COLLECTOR 1 Q20 2X C4 1pF Q22 45X Q18 Q19 R9 2.5k Q8 7 Q15 R5 5k R8 600Ω 5 R10 340Ω R20 5k R16 11Ω Q16 10X R4 5k GND-SENSE C3 6pF R7 2.5k 4 R3 5k R MID R12 1k 5X R6 8.5k Q4 RTOP COMP 2 Q21 2.5X R14 11Ω R21 100k R18 50k R19 3.6Ω 6 GND-FORCE LT1431 SD01 Package Description J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) .300 BSC (7.62 BSC) .008 – .018 (0.203 – 0.457) .200 (5.080) MAX CORNER LEADS OPTION (4 PLCS) 0° – 15° .015 – .060 (0.381 – 1.524) .023 – .045 (0.584 – 1.143) HALF LEAD OPTION .045 – .068 (1.143 – 1.650) FULL LEAD OPTION NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS .005 (0.127) MIN .405 (10.287) MAX 8 .014 – .026 (0.360 – 0.660) .100 (2.54) BSC 6 5 .025 (0.635) RAD TYP .220 – .310 (5.588 – 7.874) 1 .045 – .065 (1.143 – 1.651) 7 2 3 4 J8 0801 .125 3.175 MIN 1431fd 11 LT1431 Package Description N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .300 – .325 (7.620 – 8.255) ( +.035 .325 –.015 8.255 +0.889 –0.381 .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .008 – .015 (0.203 – 0.381) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 ± .015* (6.477 ± 0.381) ) .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 .100 (2.54) BSC N8 1002 (0.457 ± 0.076) 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) S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .050 BSC .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 8 .245 MIN .160 ±.005 .010 – .020 × 45° (0.254 – 0.508) NOTE: 1. DIMENSIONS IN 5 .150 – .157 (3.810 – 3.988) NOTE 3 1 RECOMMENDED SOLDER PAD LAYOUT .053 – .069 (1.346 – 1.752) 0°– 8° TYP .016 – .050 (0.406 – 1.270) 6 .228 – .244 (5.791 – 6.197) .030 ±.005 TYP .008 – .010 (0.203 – 0.254) 7 .014 – .019 (0.355 – 0.483) TYP INCHES (MILLIMETERS) 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) 2 3 4 .004 – .010 (0.101 – 0.254) .050 (1.270) BSC SO8 0303 1431fd 12 LT1431 Revision History (Revision history begins at Rev D) REV DATE DESCRIPTION PAGE NUMBER D 4/10 M-Grade Parts Re-Released. Obsolete Package Shading Removed 2, 11 1431fd 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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 13 LT1431 Package Description Z Package 3-Lead Plastic TO-92 (Similar to TO-226) (Reference LTC DWG # 05-08-1410 Rev C) .180 p .005 (4.572 p 0.127) .060 p .005 (1.524p 0.127) DIA .90 (2.286) NOM .180 p .005 (4.572 p 0.127) .500 (12.70) MIN .050 UNCONTROLLED (1.270) LEAD DIMENSION MAX .016 p .003 (0.406 p 0.076) .050 (1.27) BSC 5o NOM .015 p .002 (0.381 p 0.051) BULK PACK TO-92 TAPE AND REEL REFER TO TAPE AND REEL SECTION OF LTC DATA BOOK FOR ADDITIONAL INFORMATION .060 p .010 (1.524 p 0.254) 3 2 Z3 (TO-92) 1008 REV C .098 +.016/–.04 (2.5 +0.4/–0.1) 2 PLCS .140 p .010 (3.556 p 0.127) 1 10o NOM Related Parts PART NUMBER DESCRIPTION COMMENTS LTC 3722 Synchronous Full-Bridge Controller Zero Voltage Switching, Adjustable 2VS Timing LTC3723 Synchronous Push-Pull PWM Controller 1.5A Sink, 1A Source Output Drivers, Adjustable Dead Time LTC3803 SOT-23 Flyback Controller Adjustable Slope Compensation, 200kHz Operation LTC3806 Synchronous Flyback Controller Excellent Cross Regulation, High Efficiency ® LTC3900/LTC3901 Synchronous Rectifiers for Forward and Push-Pull Converters Programmable Time Out, Reverse Inductor Current Sense LT4430 Opto-Coupler Driver in SOT-23 Overshoot Control, 600mV Reference, High Bandwidth Error Amplifier 1431fd 14 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LT 0410 REV D • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1992