Datasheet

4
LT1616
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Oscillator Frequency
TEMPERATURE (°C)
–50
SWITCHING FREQUENCY (MHz)
0.75
1.00
1.25
25
75
1616 G09
0.50
0.25
0
–25 0 50
1.50
1.75
2.00
100
SHDN Pin Current
SHDN PIN VOLTAGE
0
0
SHDN PIN CURRENT (µA)
20
40
60
80
100
120
5101520
1616 G10
25
UU
U
PI FU CTIO S
BOOST (Pin 1): The BOOST pin is used to provide a drive
voltage, higher than the input voltage, to the internal
bipolar NPN power switch.
GND (Pin 2): Tie the GND pin to a local ground plane below
the LT1616 and the circuit components. Return the feed-
back divider to this pin.
FB (Pin 3): The LT1616 regulates its feedback pin to 1.25V.
Connect the feedback resistor divider tap to this pin. Set
the output voltage according to V
OUT
= 1.25V (1 + R1/R2).
A good value for R2 is 10k.
SHDN (Pin 4): The SHDN pin is used to put the LT1616 in
shutdown mode. Tie to ground to shut down the LT1616.
Tie to 2V or more for normal operation. If the shutdown
feature is not used, tie this pin to the V
IN
pin.
V
IN
(Pin 5): The V
IN
pin supplies current to the LT1616’s
internal regulator and to the internal power switch. This pin
must be locally bypassed.
SW (Pin 6): The SW pin is the output of the internal power
switch. Connect this pin to the inductor, catch diode and
boost capacitor.
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