LT1575 Linear Technology Corporation, LT1575 Datasheet
LT1575
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LT1575 Summary of contents
Page 1
... A multifunction Shutdown pin provides either current limit time-out with latchoff, overvoltage protec- tion, thermal shutdown or a combination of these func- tions. The LT1575 is available in 8-pin SO or PDIP and the LT1577 is available in 16-pin narrow body SO. , LTC and LT are registered trademarks of Linear Technology Corporation. ...
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... N8 PACKAGE S8 PACKAGE 8-LEAD PDIP 8-LEAD PLASTIC 100 C, = 100 C/ W (N8) JMAX 100 C, = 130 C/ W (S8) JMAX JA ORDER PART NUMBER LT1575CN8-1.5 LT1575CS8-3.3 LT1575CS8-1.5 LT1575CN8-3.5 LT1575CN8-2.8 LT1575CS8-3.5 LT1575CS8-2.8 LT1575CN8-5 LT1575CN8-3.3 LT1575CS8-5 S8 PART MARKING 157535 157515 15755 157528 157533 16 IPOS1 15 INEG1 14 GATE1 13 COMP1 12 IPOS2 11 ...
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... FB Input Bias Current FB I OUT Divider Current OUT A LT1575 Large-Signal Voltage Gain VOL LT1575-1.5 Large-Signal Voltage Gain LT1575-2.8 Large-Signal Voltage Gain LT1575-3.3 Large-Signal Voltage Gain LT1575-3.5 Large-Signal Voltage Gain LT1575-5 Large-Signal Voltage Gain V GATE Output Swing Low (Note GATE Output Swing High ...
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... TEMPERATURE ( C) 1575/77 G07 4 Adjustable LT1575 V REF vs Temperature 1.222 1.220 1.218 1.216 1.214 1.212 1.210 1.208 1.206 1.204 1.202 1.200 1.198 175 –75 –50 –25 ...
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... TEMPERATURE ( C) 0 – 0.1 – 0.2 IPOS = 20V – 0.3 – 0.4 – 0.5 –75 75 100 125 150 175 1575/77 G16 LT1575/LT1577 Gain and Phase vs Frequency 200 150 PHASE 100 GAIN 10k 100k 1M 150 175 FREQUENCY (Hz) 1575/77 G11 IPOS + INEG Supply Current vs Temperature ...
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... LT1575/LT1577 W U TYPICAL PERFORMANCE CHARACTERISTICS SHDN Sink Current vs Temperature 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 –75 – 50 – 100 125 150 175 TEMPERATURE ( C) 1575/77 G18 SHDN High Clamp Voltage vs Temperature 2.1 2.0 1.9 1.8 1.7 1.6 1.5 –75 – 50 – TEMPERATURE ( C) 6 SHDN Source Current vs Temperature –10 – 11 – 12 – 13 – 14 – ...
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... Tie the top of the external resistor divider directly to the output voltage for best regulation performance. OUT (Pin 4): This is the inverting input of the error amplifier for the fixed voltage LT1575. The fixed voltage parts contain a precision resistor divider network to set output voltage. The typical resistor divider current is 1mA into the pin ...
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... LT1575/LT1577 W BLOCK DIAGRAM SW1 NORMALLY SHDN OPEN SW2 NORMALLY CLOSED V IN START-UP GND FB 8 LT1575 Adjustable Voltage OR1 + COMP1 R2 – 100mV HYSTERESIS OR2 1.21V V REF I3 100 50k V TH1 50mV IPOS + I AMP INEG LIM – D1 – D2 COMP2 + + V TH2 ...
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... A OR1 SW1 NORMALLY OPEN SHDN OR2 SW2 NORMALLY CLOSED V IN START-UP V REF GND OUT R3* R4 R3/R4)V OUT REF LT1575 Fixed Voltage + COMP1 R2 – 100mV HYSTERESIS 1.21V Q7 I3 100 50k LT1575/LT1577 IPOS + V I AMP TH1 LIM INEG 50mV – ...
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... The primary block diagram elements consist of a simple feedback control loop and the secondary block diagram elements consist of multiple protection functions. Exam- ining the block diagram for the LT1575, a start-up circuit provides controlled start-up for the IC, including the precision-trimmed bandgap reference, and establishes all internal current and voltage biasing ...
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... FB pin in the adjustable voltage version and the OUT pin in the fixed voltage version. In both cases, a resistor divider network senses the output voltage and sets the regulated DC bias point. In general, the LT1575 regulator feedback loop permits a loop crossover fre- quency on the order of 1MHz while maintaining good phase and gain margins ...
Page 12
... SHDN pin for thermal shutdown. Restoring normal operation after the load current fault is cleared is accomplished in two ways. One option is to recycle the nominal 12V LT1575 supply voltage as long as an external bleed path for the Shutdown pin capacitor is provided. The second option is to provide an active reset ...
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... LT1575 feedback loop is that turn-on overshoot is virtually nonexistent in a properly compensated system. An additional circuit feature is built-in to the LT1575 fixed voltage versions. When the regulator circuit starts up, it must charge up the output capacitors. The output voltage ...
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... LT1575/LT1577 U TYPICAL APPLICATIONS Setting Output Voltage with the Adjustable LT1575 V OUT 1.21V(1 + R2/R1) OUT 1575 TA03 Setting Current Limit IPOS SENSE INEG Q2 GATE V OUT *I = 50mV/R LIM SENSE R = DISCRETE SHUNT RESISTOR OR SENSE R = KELVIN-SENSED PC BOARD TRACE SENSE ACTIVATING CURRENT LIMIT ALSO ACTIVATES ...
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... V INEG 0. GND GATE 4 5 OUT COMP R3 C4 4.99k 10pF NOTE: LTC RECOMMENDS CENTRALLY LOCATING THE LT1575-1.5 OUTPUT TO MINIMIZE V DISTRIBUTION TT DROPS AND USING SEPARATE V REF GENERATORS AT EACH BUS END LT1262 1 – C1 SHDN GND 3 – ...
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... D1, CMDSH C2, 1000pF 7 – S PGND + MBRS330T3 C4, 4 =COILTRONICS CTX02-13199 Q2, Q3 =SILICONIX SUD50N03-10 Transient Response to a 10A Load Step 200 s/DIV LT1575 1 8 SHDN IPOS INEG GND GATE IRLZ44 4 5 OUT COMP C21, 10pF R9 2k ...
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... F U Dimensions in inches (millimeters) unless otherwise noted. N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 8 0.255 0.015* (6.477 0.381) 1 0.045 – 0.065 (1.143 – 1.651) 0.065 (1.651) TYP 0.100 0.010 (2.540 0.254) LT1575/LT1577 IRL3303 5 V CORE R1 2.8V 4.7k C5 ...
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... LT1575/LT1577 PACKAGE DESCRIPTION 0.010 – 0.020 (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.016 – 0.050 0.406 – 1.270 * 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" ...
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... DWG # 05-08-1610 0.228 – 0.244 (5.791 – 6.197 0.053 – 0.069 (1.346 – 1.752) 0 – 8 TYP 0.014 – 0.019 (0.355 – 0.483) LT1575/LT1577 0.386 – 0.394* (9.804 – 10.008 0.150 – 0.157** (3.810 – 3.988) 3 ...
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... LT1575/LT1577 U TYPICAL APPLICATION FAULT RESET INPUT 330 F 6.3V 1/2 LT1577 1 SHDN1 IPOS1 2 V INEG1 12V IN1 3 GND1 GATE1 C3 0. OUT-3.3 COMP1 RELATED PARTS PART NUMBER DESCRIPTION LTC1266 Current Mode, Step-Up/Down Switching Regulator Controller LTC1392 Micropower Temperature, Power Supply and Differential ...