Datasheet LT3505 (Analog Devices) - 6
| Manufacturer | Analog Devices |
| Description | 1.2A, Step-Down Switching Regulator in 3mm × 3mm DFN |
| Pages / Page | 24 / 6 — Switch Current Limit. Switch Current Limit, RT = 75.0k. Typical Minimum … |
| File Format / Size | PDF / 832 Kb |
| Document Language | English |
Switch Current Limit. Switch Current Limit, RT = 75.0k. Typical Minimum On Time. RT Pin Bias Voltage. Switching Frequency
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LT3505 TYPICAL PERFORMANCE CHARACTERISTICS
Switch Current Limit Switch Current Limit, RT = 75.0k Typical Minimum On Time
2.0 1.8 160 TA = 25°C 1.9 140 1.7 1.8 120 1.7 1.6 1.6 100 1.5 1.5 80 1.4 60 1.3 1.4 MINIMUM ON TIME (ns) 40 SWITCH CURRENT LIMIT (A) 1.2 SWITCH CURRENT LIMIT (A) 1.3 1.1 20 1.0 1.2 0 –50 –25 0 25 50 75 100 125 0 10 20 30 40 50 60 70 80 90 100 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) DUTY CYCLE (%) TEMPERATURE (°C) 3505 G20
RT Pin Bias Voltage Switching Frequency Switching Frequency
505 3.0 VFB = 0.78V TA = 25°C TA = 25°C 500 2.5 2.0 1 495 1.5 490 BIAS VOLTAGE (mV) 1.0 485 SWITCHING FREQUENCY (MHz) 0.5 SWITCHING FREQUENCY (MHz) 480 0 0.1 –50 –25 0 25 50 75 100 125 0 5 10 15 20 25 30 35 10 100 TEMPERATURE(°C) RT PIN BIAS CURRENT (µA) RT PIN RESISTANCE (kΩ) 3505 G24
Operating Waveforms, Operating Waveforms Discontinuous Mode
VSW VSW 5V/DIV 5V/DIV IL 0.5A/DIV IL 0.5A/DIV 0 0 VOUT VOUT 20mV/DIV 20mV/DIV VIN = 12V 1µs/DIV 3505 G18 1µs/DIV 3505 F26 VIN = 12V VOUT = 3.3V VOUT = 3.3V IOUT = 0.5A IOUT = 50mA L = 10µH L = 10µH COUT = 10µF COUT = 10µF RT = 75.0k RT = 75.0k 3505fc 6
Switch Current Limit Switch Current Limit, RT = 75.0k Typical Minimum On Time
2.0 1.8 160 TA = 25°C 1.9 140 1.7 1.8 120 1.7 1.6 1.6 100 1.5 1.5 80 1.4 60 1.3 1.4 MINIMUM ON TIME (ns) 40 SWITCH CURRENT LIMIT (A) 1.2 SWITCH CURRENT LIMIT (A) 1.3 1.1 20 1.0 1.2 0 –50 –25 0 25 50 75 100 125 0 10 20 30 40 50 60 70 80 90 100 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) DUTY CYCLE (%) TEMPERATURE (°C) 3505 G20
RT Pin Bias Voltage Switching Frequency Switching Frequency
505 3.0 VFB = 0.78V TA = 25°C TA = 25°C 500 2.5 2.0 1 495 1.5 490 BIAS VOLTAGE (mV) 1.0 485 SWITCHING FREQUENCY (MHz) 0.5 SWITCHING FREQUENCY (MHz) 480 0 0.1 –50 –25 0 25 50 75 100 125 0 5 10 15 20 25 30 35 10 100 TEMPERATURE(°C) RT PIN BIAS CURRENT (µA) RT PIN RESISTANCE (kΩ) 3505 G24
Operating Waveforms, Operating Waveforms Discontinuous Mode
VSW VSW 5V/DIV 5V/DIV IL 0.5A/DIV IL 0.5A/DIV 0 0 VOUT VOUT 20mV/DIV 20mV/DIV VIN = 12V 1µs/DIV 3505 G18 1µs/DIV 3505 F26 VIN = 12V VOUT = 3.3V VOUT = 3.3V IOUT = 0.5A IOUT = 50mA L = 10µH L = 10µH COUT = 10µF COUT = 10µF RT = 75.0k RT = 75.0k 3505fc 6
