Datasheet LT1934, LT1934 (Analog Devices) - 5

LT1934/LT1934-1
TYPICAL PERFORMANCE CHARACTERISTICS Quiescent Current Undervoltage Lockout vs Temperature vs Temperature
20 4.0 15 3.5 10 3.0 UVLO (V) 5 2.5 QUIESCENT CURRENT (μA) 0 2.0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) 1934 G10 1934 G11
Minimum Input Voltage Minimum Input Voltage V V OUT = 3.3V OUT = 5V
6.0 8 LT1934 LT1934 VOUT = 3.3V VOUT = 5V 5.5 TA = 25°C TA = 25°C BOOST DIODE TIED TO OUTPUT 7 BOOST DIODE TIED TO OUTPUT 5.0 V V IN TO START IN TO START 4.5 6 V 4.0 IN TO RUN INPUT VOLTAGE (V) INPUT VOLTAGE (V) VIN TO RUN 5 3.5 3.0 4 0.1 1 10 100 0.1 1 10 100 LOAD CURRENT (mA) LOAD CURRENT (mA) 1934 G12 1934 G13
PIN FUNCTIONS (TSOT-23/DFN) BOOST (Pin 1/Pin 1):
The BOOST pin is used to provide a in shutdown mode. Tie to ground to shut down the LT1934. drive voltage, higher than the input voltage, to the internal Apply 2.3V or more for normal operation. If the shutdown bipolar NPN power switch. feature is not used, tie this pin to the VIN pin.
GND (Pin 2/Pin 5):
Tie the GND pin to a local ground plane
VIN (Pin 5/Pin 3):
The VIN pin supplies current to the below the LT1934 and the circuit components. Return the LT1934’s internal regulator and to the internal power feedback divider to this pin. switch. This pin must be locally bypassed.
FB (Pin 3/Pin 6):
The LT1934 regulates its feedback pin
SW (Pin 6/Pin 2):
The SW pin is the output of the internal to 1.25V. Connect the feedback resistor divider tap to this power switch. Connect this pin to the inductor, catch diode pin. Set the output voltage according to VOUT = 1.25V and boost capacitor. (1 + R1/R2) or R1 = R2 (VOUT/1.25 – 1).
Exposed Pad (Pin 7, DFN Package):
This pin must be
SHDN (Pin 4/Pin 4):
The SHDN pin is used to put the LT1934 soldered to ground plane. 1934fe 5