Datasheet LT3688 (Analog Devices) - 5
| Manufacturer | Analog Devices |
| Description | Dual 800mA Step-Down Switching Regulator with Power-On Reset and Watchdog Timer |
| Pages / Page | 28 / 5 — TYPICAL PERFORMANCE CHARACTERISTICS. TA = 25°C unless otherwise noted. … |
| File Format / Size | PDF / 430 Kb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. TA = 25°C unless otherwise noted. No-Load Supply Current. No-Load Supply Current (Input)
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LT3688
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted. No-Load Supply Current No-Load Supply Current (Input) (Temperature) Maximum Load Current (5V)
160 3000 2 VOUT1 = 5V CATCH DIODE: B140HB fSW = 1MHz 140 VOUT2 = 3.3V VIN = 12V 2500 VOUT1 = 5V 120 VOUT2 = 3.3V 1.5 L = 15μH 2000 100 L = 10μH 80 1500 1 INCREASED SUPPLY Y CURRENT (μA) Y CURRENT (μA) CURRENT DUE TO CATCH 60 1000 DIODE LEAKAGE AT HIGH LOAD CURRENT (A) SUPPL TEMPERATURE 40 SUPPL 0.5 500 20 0 0 0 0 10 20 30 40 –50 –25 0 25 50 75 100 125 150 0 10 20 30 40 VIN (V) TEMPERATURE (°C) INPUT VOLTAGE (V) 3688 G04 3688 G05 3688 G06
Switch Current Limit Switch Current Limit Maximum Load Current (3.3V) vs Duty Cycle vs Temperature
2 1.8 2.0 fSW = 1MHz TYPICAL 1.6 1.5 L = 15μH 1.4 1.5 L = 10μH 1.2 MIN 1 1 1.0 0.8 LOAD CURRENT (A) 0.6 CURRENT LIMIT (A) CURRENT LIMIT (A) 0.5 0.5 0.4 0.2 DC = 15% 0 0 0 0 10 20 30 40 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 150 INPUT VOLTAGE (V) DUTY CYCLE (%) TEMPERATURE (°C) 3688 G07 3688 G08 3688 G09
Switch Voltage Drop BST Pin Current Feedback Voltage
350 25 0.810 300 20 0.805 250 15 200 TAGE (V) TAGE (mV) 0.800 150 10 SWITCH VOL 100 BST PIN CURRENT (mA) FEEDBACK VOL 0.795 5 50 0 0 0.790 0 200 400 600 800 1000 0 200 400 600 800 1000 –50 –20 0 25 50 75 100 125 150 SWITCH CURRENT (mA) SWITCH CURRENT (mA) TEMPERATURE (°C) 3688 G10 3688 G11 3688 G12 3688f 5
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted. No-Load Supply Current No-Load Supply Current (Input) (Temperature) Maximum Load Current (5V)
160 3000 2 VOUT1 = 5V CATCH DIODE: B140HB fSW = 1MHz 140 VOUT2 = 3.3V VIN = 12V 2500 VOUT1 = 5V 120 VOUT2 = 3.3V 1.5 L = 15μH 2000 100 L = 10μH 80 1500 1 INCREASED SUPPLY Y CURRENT (μA) Y CURRENT (μA) CURRENT DUE TO CATCH 60 1000 DIODE LEAKAGE AT HIGH LOAD CURRENT (A) SUPPL TEMPERATURE 40 SUPPL 0.5 500 20 0 0 0 0 10 20 30 40 –50 –25 0 25 50 75 100 125 150 0 10 20 30 40 VIN (V) TEMPERATURE (°C) INPUT VOLTAGE (V) 3688 G04 3688 G05 3688 G06
Switch Current Limit Switch Current Limit Maximum Load Current (3.3V) vs Duty Cycle vs Temperature
2 1.8 2.0 fSW = 1MHz TYPICAL 1.6 1.5 L = 15μH 1.4 1.5 L = 10μH 1.2 MIN 1 1 1.0 0.8 LOAD CURRENT (A) 0.6 CURRENT LIMIT (A) CURRENT LIMIT (A) 0.5 0.5 0.4 0.2 DC = 15% 0 0 0 0 10 20 30 40 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 150 INPUT VOLTAGE (V) DUTY CYCLE (%) TEMPERATURE (°C) 3688 G07 3688 G08 3688 G09
Switch Voltage Drop BST Pin Current Feedback Voltage
350 25 0.810 300 20 0.805 250 15 200 TAGE (V) TAGE (mV) 0.800 150 10 SWITCH VOL 100 BST PIN CURRENT (mA) FEEDBACK VOL 0.795 5 50 0 0 0.790 0 200 400 600 800 1000 0 200 400 600 800 1000 –50 –20 0 25 50 75 100 125 150 SWITCH CURRENT (mA) SWITCH CURRENT (mA) TEMPERATURE (°C) 3688 G10 3688 G11 3688 G12 3688f 5
