LTC3803 datasheet(5/12 Pages) LINER

5 / 12 page

LTC3803

3803i

BLOCK DIAGRA

–

SLOPE

COMP

CURRENT

RAMP

VCC

GATE

DRIVER NGATE

SENSE

3803 BD

200kHz

OSCILLATOR

UNDERVOLTAGE

LOCKOUT

CURRENT

COMPARATOR

SHUTDOWN

COMPARATOR

SHUTDOWN

20mV

ITH/RUN

ERROR

AMPLIFIER

VFB

SOFT-

START

CLAMP

VCC

SHUNT

REGULATOR

SWITCHING

LOGIC AND

BLANKING

CIRCUIT

0.28V

VCC < VTURNON

0.3

µA

VCC

–

GND

1.2V

800mV

REFERENCE

PI FU CTIO S

ITH/RUN (Pin 1): This pin performs two functions. It

serves as the error amplifier compensation point as well as

the run/shutdown control input. Nominal voltage range is

0.7V to 1.9V. Forcing this pin below 0.28V causes the

LTC3803 to shut down. In shutdown mode, the NGATE pin

is held low.

GND (Pin 2): Ground Pin.

VFB (Pin 3): Receives the feedback voltage from an exter-

nal resistive divider across the output.

SENSE (Pin 4): This pin performs two functions. It moni-

tors switch current by reading the voltage across an

external current sense resistor to ground. It also injects a

current ramp that develops slope compensation voltage

across an optional external programming resistor.

VCC (Pin 5): Supply Pin. Must be closely decoupled to GND

(Pin 2).

NGATE (Pin 6): Gate Drive for the External N-Channel

MOSFET. This pin swings from 0V to VCC.

LTC3803 Datasheet(PDF) 5 Page - Linear Technology

LTC3803 Datasheet(HTML) 5 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12

Datasheet Download

Link URL