Datasheet LT1959 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | 4.5A, 500kHz Step-Down Switching Regulator |
| Pages / Page | 24 / 4 — TYPICAL PERFORMANCE CHARACTERISTICS. Minimum Input Voltage with 3.3V … |
| File Format / Size | PDF / 305 Kb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. Minimum Input Voltage with 3.3V Output. Switch Peak Current Limit. Feedback Pin Voltage
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LT1959
W U TYPICAL PERFORMANCE CHARACTERISTICS Minimum Input Voltage with 3.3V Output Switch Peak Current Limit Feedback Pin Voltage
4.7 6.5 1.215 4.5 6.0 TYPICAL 4.3 5.5 4.1 5.0 MINIMUM 1.210 3.9 4.5 INPUT VOLTAGE (V) 3.7 4.0 FEEDBACK VOLTAGE (V) SWITCH PEAK CURRENT (A) 3.5 3.5 3.3 3.0 1.205 1 10 100 1000 0 20 40 60 80 100 – 50 –25 0 25 50 75 100 125 LOAD CURRENT (mA) DUTY CYCLE (%) TEMPERATURE (°C) 1959 G01 1959 G02 1959 G03
Lockout and Shutdown Shutdown Pin Bias Current Thresholds Shutdown Supply Current
–500 2.40 25 VSHDN = 0V AT 0.37V SHUTDOWN THRESHOLD. LOCKOUT – 400 AFTER SHUTDOWN, CURRENT 20 DROPS TO A FEW µA 2.36 µA) – 300 µA) 2.32 15 – 200 0.8 10 CURRENT ( – 8 START-UP AT 2.38V LOCKOUT THRESHOLD SHUTDOWN PIN VOLTAGE (V) 0.4 INPUT SUPPLY CURRENT ( 5 – 4 SHUTDOWN 0 0 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 0 5 10 15 TEMPERATURE (°C) JUNCTION TEMPERATURE (°C) INPUT VOLTAGE (V) 1959 G04 1959 G05 1959 G06
Shutdown Supply Current Error Amplifier Transconductance Error Amplifier Transconductance
70 2500 3000 200 VIN = 10V 60 PHASE 2000 2500 150 µA) 50 µMho) GAIN PHASE (DEG) 1500 2000 100 40 µMho) VC 30 1000 1500 R C OUT OUT GAIN ( 50 V ( FB 2 × 10–3) 200k 12pF 20 500 1000 INPUT SUPPLY CURRENT ( TRANSCONDUCTANCE ( ERROR AMPLIFIER EQUIVALENT CIRCUIT 0 10 RLOAD = 50Ω 0 0 500 –50 0 0.1 0.2 0.3 0.4 –50 –25 0 25 50 75 100 125 100 1k 10k 100k 1M 10M SHUTDOWN VOLTAGE (V) JUNCTION TEMPERATURE (°C) FREQUENCY (Hz) 1959 G09 1959 G08 1959 G07 4
W U TYPICAL PERFORMANCE CHARACTERISTICS Minimum Input Voltage with 3.3V Output Switch Peak Current Limit Feedback Pin Voltage
4.7 6.5 1.215 4.5 6.0 TYPICAL 4.3 5.5 4.1 5.0 MINIMUM 1.210 3.9 4.5 INPUT VOLTAGE (V) 3.7 4.0 FEEDBACK VOLTAGE (V) SWITCH PEAK CURRENT (A) 3.5 3.5 3.3 3.0 1.205 1 10 100 1000 0 20 40 60 80 100 – 50 –25 0 25 50 75 100 125 LOAD CURRENT (mA) DUTY CYCLE (%) TEMPERATURE (°C) 1959 G01 1959 G02 1959 G03
Lockout and Shutdown Shutdown Pin Bias Current Thresholds Shutdown Supply Current
–500 2.40 25 VSHDN = 0V AT 0.37V SHUTDOWN THRESHOLD. LOCKOUT – 400 AFTER SHUTDOWN, CURRENT 20 DROPS TO A FEW µA 2.36 µA) – 300 µA) 2.32 15 – 200 0.8 10 CURRENT ( – 8 START-UP AT 2.38V LOCKOUT THRESHOLD SHUTDOWN PIN VOLTAGE (V) 0.4 INPUT SUPPLY CURRENT ( 5 – 4 SHUTDOWN 0 0 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 0 5 10 15 TEMPERATURE (°C) JUNCTION TEMPERATURE (°C) INPUT VOLTAGE (V) 1959 G04 1959 G05 1959 G06
Shutdown Supply Current Error Amplifier Transconductance Error Amplifier Transconductance
70 2500 3000 200 VIN = 10V 60 PHASE 2000 2500 150 µA) 50 µMho) GAIN PHASE (DEG) 1500 2000 100 40 µMho) VC 30 1000 1500 R C OUT OUT GAIN ( 50 V ( FB 2 × 10–3) 200k 12pF 20 500 1000 INPUT SUPPLY CURRENT ( TRANSCONDUCTANCE ( ERROR AMPLIFIER EQUIVALENT CIRCUIT 0 10 RLOAD = 50Ω 0 0 500 –50 0 0.1 0.2 0.3 0.4 –50 –25 0 25 50 75 100 125 100 1k 10k 100k 1M 10M SHUTDOWN VOLTAGE (V) JUNCTION TEMPERATURE (°C) FREQUENCY (Hz) 1959 G09 1959 G08 1959 G07 4
