Datasheet LT1581, LT1581-2.5 (Analog Devices) - 4

LT1581/LT1581-2.5
W U TYPICAL PERFORMANCE CHARACTERISTICS Control Pin Current vs Dropout Voltage — Dropout Voltage — Output Current Minimum Control Voltage Minimum Power Voltage
200 2 0.8 INDICATES GUARANTEED TEST POINTS INDICATES GUARANTEED TEST POINTS INDICATES GUARANTEED TEST POINTS 180 0.7 160 0.6 DATA SHEET LIMIT 140 ) (V) (V) 0.5 DATA SHEET LIMIT 120 OUT OUT DATA SHEET LIMIT 100 – V 1 – V 0.4 80 T T J = 125°C J = 25°C TYPICAL 0.3 CONTROL POWER TJ = 125°C 60 DEVICE (V (V 0.2 TJ = 25°C CONTROL PIN CURRENT (mA) 40 MINIMUM CONTROL VOLTAGE MINIMUM POWER VOLTAGE (V) 0.1 20 0 0 0 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 OUTPUT CURRENT (A) OUTPUT CURRENT (A) OUTPUT CURRENT (A) 1581 G01 1581 G02 1581 G03
LT1581 Reference Voltage vs LT1581-2.5 Output Voltage vs Temperature Temperature Load Current Step Response
1.262 2.512 1.259 2.509 VOUT 50mV/DIV 1.256 2.506 1.253 2.503 1.250 2.500 10A 1.247 2.497 LOAD OUTPUT VOLTAGE (V) REFERENCE VOLTAGE (V) 1.244 2.494 400mA 50µs/DIV 1581 G06 1.241 2.491 1.238 2.488 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 TEMPERATURE ( TEMPERATURE ( °C) °C) 1581 G05 1581 G04
U U U PIN FUNCTIONS ADJUST (Pin 1):
This pin is the negative side of the
OUTPUT (Pin 4):
This is the power output of the device. reference voltage for the device. Transient response can
V
be improved by adding a small bypass capacitor from the
POWER (Pin 5):
This is the collector to the power device of the LT1581. The output load current is supplied through ADJUST pin to ground. For fixed voltage devices the this pin. For the device to regulate, the voltage at this pin ADJUST pin is also brought out to allow the user to add a must be between 0.1V and 0.7V greater than the output bypass capacitor. voltage (see Dropout specifications).
GND (Pin 2, Fixed Voltage Devices Only):
For fixed
V
voltage devices this is the bottom of the resistor divider
CONTROL (Pin 6):
This pin is the supply pin for the control circuitry of the device. The current flow into this pin will that sets the output voltage. be about 1% of the output current. For the device to
SENSE (Pin 3):
This pin is the positive side of the reference regulate, the voltage at this pin must be between 1.0V and voltage for the device. With this pin it is possible to Kelvin 1.35V greater than the output voltage (see Dropout sense the output voltage at the load. specifications). 4