LTC3772B Datasheet, PDF (6/20 Pages) Linear Technology – Micropower No RSENSE Constant Frequency Step-Down DC/DC Controller

LTC3772B
PI FU CTIO S (DDB/TS8)
GND (Pin 1/Pin 4): Ground Pin.
V_FB (Pin 2/Pin 3): Receives the feedback voltage from an
external resistor divider across the output.
I_TH/RUN (Pin 3/Pin 2): This pin performs two functions. It
serves as the error amplifier compensation point as well as
the run control input. Nominal voltage range for this pin is
0.7V to 1.9V. Forcing this pin below 0.6V causes the
device to be shut down. In shutdown, all functions are
disabled and the PGATE pin is held high.
I_PRG (Pin 4/Pin 1): Current Sense Limit Pin. Three-state
pin selects maximum peak sense voltage threshold. The
pin selects the maximum voltage drop across the external
P-channel MOSFET. Tie to V_IN, GND or float to select
208mV, 70mV or 138mV respectively.
NC (Pin 5/Pin 8): No Connection Required.
SW (Pin 6/Pin 7): Switch Node Connection to Inductor
and Current Sense Input Pin. Normally, the external
P-channel MOSFET’s drain is connected to this pin.
V_IN (Pin 7/Pin 6): Supply and Current Sense Input Pin.
This pin must be closely decoupled to GND (Pin 4).
Normally the external P-channel MOSFET’s source is
connected to this pin.
PGATE (Pin 8/Pin 5): Gate Drive for the External P-Channel
MOSFET. This pin swings from 0V to V_IN.
Exposed Pad (Pin 9, DDB Only): The Exposed Pad is
ground and must be soldered to the PCB for electrical
connection and optimum thermal performance.
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