LT1943 LINER [Linear Technology], LT1943 Datasheet
LT1943
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LT1943 Summary of contents
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... E3 232k FB3 GND 10.0k SGND VC3 VC4 2.2 F 0.47 F 13k 47.5k 100pF 100pF 2.2nF 680pF 1943 F01 Final Electrical Specifications LT1943 September 2003 U with up to LOGIC DD signal and can handle disabled if any ON DD Startup Waveforms RUN-SS 2V/DIV V LOGIC 5V/DIV AV DD 10V/DIV ...
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... RUN-SS, SS-234 = 0.4V BIAS = 3.1V, All Switches Off (Note 3) All FB Pins = 1.5V All FB Pins = 1.5V V Current = 30mA 30V 36V PGOOD All FB Pins = 0V 200kHz ORDER PART NUMBER 28 SW2 27 SW2 LT1943EFE PGOOD 22 BIAS 21 SW3 20 GND 19 SW4 FE PART MARKING 18 RUN-SS SS-234 17 1943EFE ...
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... Duty Cycle = 35 FB1 = 1. 1. 1.5A SW 4.5V < V < 22V IN (Note SW2 FB2 = 1. SW2 4.5V < V < 22V IN (Note 0.2A SW3 FB3 = 1. 0.2A SW3 I = 170mA LT1943 MIN TYP MAX UNITS 1.23 1.25 1.27 V 1.22 1.27 V 0.01 0.03 %/V 100 600 nA 200 V/V 450 mhos 2.4 3.2 4.3 A 310 470 mV 0 1.8 2 ...
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... Maximum Duty Cycle (SW4) Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LT1943E is guaranteed to meet performance specifications from Specifications over the – operating temperature range are assured by design, characterization, and correlation with statistical process controls ...
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... TEMPERATURE ( C) 1943 G08 SW3 V CESAT 500 400 300 200 100 0 0 0.1 0.2 0.3 0.4 SW3 CURRENT (A) 1943 G11 LT1943 SW2 Current Limit 5.0 4.5 4.0 3.5 3.0 2.5 –50 – 100 125 TEMPERATURE ( C) 1943 G06 SW1 V CESAT 600 500 400 ...
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... LT1943 W U TYPICAL PERFOR A CE CHARACTERISTICS V Current Limit ON 100 (V) ON 1943 G13 Reference Voltage 1.27 1.26 1.25 1.24 1.23 1.22 –50 –25 0 TEMPERATURE ( C) 6 Oscillator Frequency 1.4 1.3 1.2 1.1 1.0 –50 – TEMPERATURE ( C) Bias Pin Current 100 SW2 ...
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... V (Pins 15, 16): The V IN according to LOGIC LT1943’s internal regulator and to the internal power transistor for switch 1. These pins must be tied together and locally bypassed. SS-234 (Pin 17): This is the soft-start pin for switching = 1.25 • DD regulators 2, 3 and 4. Place a soft-start capacitor here to limit start-up inrush current and output voltage ramp rate ...
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... LT1943 CTIO S SW3 (Pin 21): This is the collector of the internal NPN bipolar power transistor for switching regulator 3. Mini- mize metal trace area at this pin to keep EMI down. BIAS (Pin 22): The BIAS pin is used to improve efficiency when operating at higher input voltages. Connecting this ...
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... OSCILLATOR SLOPE COMPENSATION – + – – 1.25V S Q FOLDBACK OSCILLATOR SLOPE COMPENSATION – gm – + 1.25V + S Q FOLDBACK OSCILLATOR SLOPE COMPENSATION Figure 2. LT1943 BOOST DRIVER SW1 SWITCH VC1 R10 10 C11 C20 VC2 R11 3 C21 C12 BIAS 22 SW2 ...
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... LT1943 U OPERATIO The LT1943 is a highly integrated power supply IC con- taining four separate switching regulators. All four switch- ers have their own oscillator with frequency foldback and use current mode control. Switching regulator 1 consists of a step-down regulator with a current limit of 2.4A. Switching regulator boost regulator with a current limit of 2 ...
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... PACKAGE 0.45 0.05 1.05 0.10 0.65 BSC 1 0 – 8 0.65 0.45 – 0.75 (.0256) BSC 4. RECOMMENDED MINIMUM PCB METAL SIZE FOR EXPOSED PAD ATTACHMENT *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.150mm (.006") PER SIDE LT1943 9.60 – 9.80* (.378 – .386) 4.75 (.187 2.74 (.108 ...
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... FAX: (408) 434-0507 www.linear.com 5V Input, Quad Output TFT-LCD Power Supply SW3 IN SW4 SW2 NFB4 FB2 RUN-SS LT1943 SS-234 FB4 C T BIAS PGOOD BOOST SW1 FB3 FB1 GND SGND VC1 VC2 VC3 VC4 27 ...