Datasheet LT1943 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | High Current Quad Output Regulator for TFT LCD Panels |
| Pages / Page | 20 / 4 — ELECTRICAL CHARACTERISTICS The |
| File Format / Size | PDF / 278 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS The
Model Line for this Datasheet
Text Version of Document
LT1943
ELECTRICAL CHARACTERISTICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. RUN-SS, SS-234 = 2.5V unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS SWITCH 4 (350mA INVERTER)
FB4 Voltage 1.23 1.25 1.27 V ● 1.22 1.27 V FB4 Voltage Line Regulation 4.5V < VIN < 22V 0.01 0.03 %/V FB4 Pin Bias Current (Note 4) ● 100 600 nA NFB4 Voltage (VFB4-VNFB4) 1.215 1.245 1.275 V ● 1.205 1.275 V NFB4 Voltage Line Regulation 4.5V < VIN < 22V 0.01 0.03 %/V NFB4 Pin Bias Current (Note 5) 100 600 nA Error Amplifier 4 Voltage Gain 200 V/V Error Amplifier 4 Transconductance ∆I = 5µA 450 µmhos Switch 4 Current Limit ● 0.35 0.5 0.7 A Switch 4 VCESAT ISW4 = 0.3A 260 390 mV Switch 4 Leakage Current FB4 = 1.5V 0.1 1 µA BIAS Pin Current due to SW4 ISW4 = 0.3A 15 mA Maximum Duty Cycle (SW4) 84 88 % ● 83 %
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
Current flows into FB1, FB2, FB3 and FB4 pins. of a device may be impaired.
Note 5:
Current flows out of NFB4 pin.
Note 2:
The LT1943E is guaranteed to meet performance specifications
Note 6:
Current limit is guaranteed by design and/or correlation to static from 0°C to 70°C. Specifications over the –40°C to 85°C operating test. Slope compensation reduces current limit at high duty cycle. temperature range are assured by design, characterization, and correlation
Note 7:
This is the minimum voltage across the boost capacitor needed to with statistical process controls. guarantee full saturation of the internal power switch.
Note 3:
The CT pin is held low until FB1, FB2, FB3 and FB4 all ramp above the FB threshold offset.
W U TYPICAL PERFOR A CE CHARACTERISTICS Maximum Output Current for VLOGIC = 3.3V SW1 Current Limit vs Duty Cycle SW1 Current Limit
2.8 5 4.5 TA = 25°C TA = 25°C 2.6 4 2.4 4.0 L1 = 4.7µH TYPICAL 2.2 3 L1 = 3.3µH 2.0 3.5 2 1.8 SW1 CURRENT (A) MINIMUM SW1 CURRENT (A) 1.6 3.0 MAXIMUM OUTPUT CURRENT (A) 1 LOGIC 1.4 V 1.2 0 2.5 0 5 10 15 20 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 INPUT VOLTAGE (V) DUTY CYCLE (%) TEMPERATURE (°C) 1943 G01 1943 G02 1943 G03 1943fa 4
ELECTRICAL CHARACTERISTICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. RUN-SS, SS-234 = 2.5V unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS SWITCH 4 (350mA INVERTER)
FB4 Voltage 1.23 1.25 1.27 V ● 1.22 1.27 V FB4 Voltage Line Regulation 4.5V < VIN < 22V 0.01 0.03 %/V FB4 Pin Bias Current (Note 4) ● 100 600 nA NFB4 Voltage (VFB4-VNFB4) 1.215 1.245 1.275 V ● 1.205 1.275 V NFB4 Voltage Line Regulation 4.5V < VIN < 22V 0.01 0.03 %/V NFB4 Pin Bias Current (Note 5) 100 600 nA Error Amplifier 4 Voltage Gain 200 V/V Error Amplifier 4 Transconductance ∆I = 5µA 450 µmhos Switch 4 Current Limit ● 0.35 0.5 0.7 A Switch 4 VCESAT ISW4 = 0.3A 260 390 mV Switch 4 Leakage Current FB4 = 1.5V 0.1 1 µA BIAS Pin Current due to SW4 ISW4 = 0.3A 15 mA Maximum Duty Cycle (SW4) 84 88 % ● 83 %
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
Current flows into FB1, FB2, FB3 and FB4 pins. of a device may be impaired.
Note 5:
Current flows out of NFB4 pin.
Note 2:
The LT1943E is guaranteed to meet performance specifications
Note 6:
Current limit is guaranteed by design and/or correlation to static from 0°C to 70°C. Specifications over the –40°C to 85°C operating test. Slope compensation reduces current limit at high duty cycle. temperature range are assured by design, characterization, and correlation
Note 7:
This is the minimum voltage across the boost capacitor needed to with statistical process controls. guarantee full saturation of the internal power switch.
Note 3:
The CT pin is held low until FB1, FB2, FB3 and FB4 all ramp above the FB threshold offset.
W U TYPICAL PERFOR A CE CHARACTERISTICS Maximum Output Current for VLOGIC = 3.3V SW1 Current Limit vs Duty Cycle SW1 Current Limit
2.8 5 4.5 TA = 25°C TA = 25°C 2.6 4 2.4 4.0 L1 = 4.7µH TYPICAL 2.2 3 L1 = 3.3µH 2.0 3.5 2 1.8 SW1 CURRENT (A) MINIMUM SW1 CURRENT (A) 1.6 3.0 MAXIMUM OUTPUT CURRENT (A) 1 LOGIC 1.4 V 1.2 0 2.5 0 5 10 15 20 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 INPUT VOLTAGE (V) DUTY CYCLE (%) TEMPERATURE (°C) 1943 G01 1943 G02 1943 G03 1943fa 4
