Datasheet LT3975 (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | 42V, 2.5A, 2MHz Step-Down Switching Regulator with 2.7µA Quiescent Current |
| Pages / Page | 24 / 7 — TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. SS … |
| File Format / Size | PDF / 295 Kb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. SS Pin Current. Boost Capacitor Charger
Model Line for this Datasheet
Text Version of Document
LT3975
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. SS Pin Current Boost Capacitor Charger Boost Diode Forward Voltage
2.6 160 1.6 VSS = 0.5V VBST = VIN 2.4 140 1.4 2.2 120 1.2 2.0 100 1.0 1.8 80 0.8 1.6 60 0.6 SS PIN CURRENT (µA) 1.4 OUT PIN CURRENT (mA) 40 BOOST DIODE VOLTAGE (V) 0.4 1.2 20 0.2 1.0 0 0 –55 –25 5 35 65 95 125 155 0 2 4 6 8 10 12 14 16 0 0.5 1 1.5 2 TEMPERATURE (°C) OUT PIN VOLTAGE (V) BOOST DIODE CURRENT (A) 3975 G28 3975 G29 3975 G30
Dropout Comparator Thresholds Start-Up/Dropout Performance Start-Up/Dropout Performance
600 580 VIN V VIN VIN 1V/DIV IN 1V/DIV 560 VOUT VOUT 540 VOUT RISING 520 VOUT VOUT 1V/DIV 1V/DIV 500 480 VOUT FALLING 460 2.5Ω LOAD 100ms/DIV 3975 G32 1kΩ LOAD 100ms/DIV 3975 G33 (2A IN REGULATION) (5mA IN REGULATION) DROPOUT THRESHOLD (mV) 440 420 400–55 –25 5 35 65 95 125 155 TEMPERATURE (°C) 3975 G31
Full Frequency Switching Burst Mode Switching Waveforms Waveforms Dropout Switching Waveforms
V V V SW SW SW 5V/DIV 5V/DIV 2V/DIV IL IL IL 0.5A/DIV 1A/DIV 1A/DIV VOUT VOUT VOUT 10mV/DIV 20mV/DIV 50mV/DIV V 3975 G34 3975 G35 3975 G36 IN = 12V 5µs/DIV VIN = 12V 1µs/DIV VIN = 5V 5µs/DIV VOUT = 3.3V VOUT = 3.3V VOUT SET FOR 5V ILOAD = 20mA ILOAD = 1A ILOAD = 0.5A COUT = 47µF COUT = 47µF COUT = 47µF 3975f 7 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION TYPICAL APPLICATION RELATED PARTS
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. SS Pin Current Boost Capacitor Charger Boost Diode Forward Voltage
2.6 160 1.6 VSS = 0.5V VBST = VIN 2.4 140 1.4 2.2 120 1.2 2.0 100 1.0 1.8 80 0.8 1.6 60 0.6 SS PIN CURRENT (µA) 1.4 OUT PIN CURRENT (mA) 40 BOOST DIODE VOLTAGE (V) 0.4 1.2 20 0.2 1.0 0 0 –55 –25 5 35 65 95 125 155 0 2 4 6 8 10 12 14 16 0 0.5 1 1.5 2 TEMPERATURE (°C) OUT PIN VOLTAGE (V) BOOST DIODE CURRENT (A) 3975 G28 3975 G29 3975 G30
Dropout Comparator Thresholds Start-Up/Dropout Performance Start-Up/Dropout Performance
600 580 VIN V VIN VIN 1V/DIV IN 1V/DIV 560 VOUT VOUT 540 VOUT RISING 520 VOUT VOUT 1V/DIV 1V/DIV 500 480 VOUT FALLING 460 2.5Ω LOAD 100ms/DIV 3975 G32 1kΩ LOAD 100ms/DIV 3975 G33 (2A IN REGULATION) (5mA IN REGULATION) DROPOUT THRESHOLD (mV) 440 420 400–55 –25 5 35 65 95 125 155 TEMPERATURE (°C) 3975 G31
Full Frequency Switching Burst Mode Switching Waveforms Waveforms Dropout Switching Waveforms
V V V SW SW SW 5V/DIV 5V/DIV 2V/DIV IL IL IL 0.5A/DIV 1A/DIV 1A/DIV VOUT VOUT VOUT 10mV/DIV 20mV/DIV 50mV/DIV V 3975 G34 3975 G35 3975 G36 IN = 12V 5µs/DIV VIN = 12V 1µs/DIV VIN = 5V 5µs/DIV VOUT = 3.3V VOUT = 3.3V VOUT SET FOR 5V ILOAD = 20mA ILOAD = 1A ILOAD = 0.5A COUT = 47µF COUT = 47µF COUT = 47µF 3975f 7 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION TYPICAL APPLICATION RELATED PARTS
