Datasheet LT1616 (Analog Devices) - 4

LT1616
W U TYPICAL PERFOR A CE CHARACTERISTICS Oscillator Frequency SHDN Pin Current
2.00 120 1.75 100 1.50 µA) 80 1.25 1.00 60 0.75 40 0.50 SHDN PIN CURRENT ( SWITCHING FREQUENCY (MHz) 20 0.25 0 0 –50 –25 0 25 50 75 100 0 5 10 15 20 25 TEMPERATURE (°C) SHDN PIN VOLTAGE 1616 G09 1616 G10
U U U PI FU CTIO S BOOST (Pin 1):
The BOOST pin is used to provide a drive
SHDN (Pin 4):
The SHDN pin is used to put the LT1616 in voltage, higher than the input voltage, to the internal shutdown mode. Tie to ground to shut down the LT1616. bipolar NPN power switch. Tie to 2V or more for normal operation. If the shutdown feature is not used, tie this pin to the V
GND (Pin 2):
Tie the GND pin to a local ground plane below IN pin. the LT1616 and the circuit components. Return the feed-
VIN (Pin 5):
The VIN pin supplies current to the LT1616’s back divider to this pin. internal regulator and to the internal power switch. This pin must be locally bypassed.
FB (Pin 3):
The LT1616 regulates its feedback pin to 1.25V. Connect the feedback resistor divider tap to this pin. Set
SW (Pin 6):
The SW pin is the output of the internal power the output voltage according to VOUT = 1.25V (1 + R1/R2). switch. Connect this pin to the inductor, catch diode and A good value for R2 is 10k. boost capacitor. 4