LTC3565_12 Datasheet, PDF (7/22 Pages) Linear Technology – 1.25A, 4MHz, Synchronous Step-Down DC/DC Converter

LTC3565
PIN FUNCTIONS
RT (Pin 1): Timing Resistor Pin. The oscillator frequency
is programmed by connecting a resistor from this pin to
ground.
RUN (Pin 2): Converter Enable Pin. Forcing this pin above
1.5V enables this part, while forcing it below 0.3V causes
the device to shut down. In shutdown, the device draws
<1μA supply current. This pin must be driven; do not float.
SYNC/MODE (Pin 3): Combination Mode Selection and
Oscillator Synchronization Pin. This pin controls the
operation of the device. When tied to SV_IN or GND, Burst
Mode operation or pulse skipping mode is selected,
respectively. If this pin is held at half of SV_IN, the forced
continuous mode is selected. The oscillation frequency
can be synchronized to an external oscillator applied to
this pin. When synchronized to an external clock, pulse
skip mode is selected.
SW (Pin 4): The Switch Node Connection to the Inductor.
This pin swings from PV_IN to GND.
GND (Pin 5, Exposed Pad Pin 11): Main Power Ground
Pin. Connect to the (–) terminal of C_OUT, and (–) terminal
of C_IN. The exposed pad must be soldered to electrical
ground on the PCB.
PV_IN (Pin 6): Main Supply Pin. Must be closely decoupled
to GND.
SV_IN (Pin 7): The Signal Power Pin. All active circuitry is
powered from this pin. Must be closely decoupled to GND.
SV_IN must be greater than or equal to PV_IN.
PGOOD (Pin 8): The Power Good Pin. This common drain
logic output is pulled to GND when the output voltage is
not within ±7% of regulation.
V_FB (Pin 9): Receives the feedback voltage from the ex-
ternal resistive divider across the output. Nominal voltage
for this pin is 0.6V.
ITH (Pin 10): Error Amplifier Compensation Point. The
current comparator threshold increases with this control
voltage. Nominal voltage range for this pin is 0.4V to
1.4V.
PIN
NAME DESCRIPTION
1
RT
Timing Resistor
2
RUN Enable Pin
3
SYNC/MODE Mode Select/Synchronization Pin
4
SW
Switch Node
5
GND Main Power Ground
6
PV_IN
Main Power Supply
7
SV_IN
Signal Power Supply
8
PGOOD Power Good Pin
9
V_FB
Output Feedback Pin
10
ITH
Error Amplifier Compensation
NOMINAL (V)
MIN
TYP
MAX
–0.3
0.4
SV_IN
–0.3
SV_IN
0
SV_IN
0
PV_IN
0
–0.3
5.5
2.5
5.5
0
SV_IN
0
0.8
1.0
0
1.5
ABSOLUTE MAX (V)
MIN
MAX
–0.3
SV_IN + 0.3
–0.3
SV_IN
–0.3
SV_IN + 0.3
–0.3
PV_IN + 0.3
–0.3
6
–0.3
6
–0.3
SV_IN + 0.3
–0.3
SV_IN + 0.3
–0.3
SV_IN + 0.3
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