LT1913 datasheet(7/24 Pages) LINER

7 / 24 page

LT1913

1913f

PI FU CTIO S

BD (Pin 1): This pin connects to the anode of the boost

Schottky diode. BD also supplies current to the internal

regulator.

BOOST (Pin 2): This pin is used to provide a drive

voltage, higher than the input voltage, to the internal bipolar

NPN power switch.

SW (Pin 3): The SW pin is the output of the internal power

switch. Connect this pin to the inductor, catch diode and

boost capacitor.

VIN (Pin 4): The VIN pin supplies current to the LT1913’s

internal regulator and to the internal power switch. This

pin must be locally bypassed.

RUN/SS (Pin 5): The RUN/SS pin is used to put the

LT1913 in shutdown mode. Tie to ground to shut down

the LT1913. Tie to 2.5V or more for normal operation. If

the shutdown feature is not used, tie this pin to the VIN

pin. RUN/SS also provides a soft-start function; see the

Applications Information section.

SYNC (Pin 6): This is the external clock synchronization

input. Ground this pin when not used. Tie to a clock source

for synchronization. Clock edges should have rise and

fall times faster than 1μs. Do not leave pin ﬂoating. See

synchronizing section in Applications Information.

PG (Pin 7): The PG pin is the open collector output of an

internal comparator. PG remains low until the FB pin is

within 9% of the ﬁnal regulation voltage. PG output is valid

when VIN is above 3.6V and RUN/SS is high.

FB (Pin 8): The LT1913 regulates the FB pin to 0.790V.

Connect the feedback resistor divider tap to this pin.

VC (Pin 9): The VC pin is the output of the internal error

ampliﬁer. The voltage on this pin controls the peak switch

current. Tie an RC network from this pin to ground to

compensate the control loop.

RT (Pin 10): Oscillator Resistor Input. Connecting a resistor

to ground from this pin sets the switching frequency.

Exposed Pad (Pin 11): Ground. The Exposed Pad must

be soldered to PCB.

LT1913 Datasheet(PDF) 7 Page - Linear Technology