LTC3736-2 Linear Technology, LTC3736-2 Datasheet - Page 7

• Manufacturer Part Number: LTC3736-2
• Description: Synchronous Controller
• Manufacturer: Linear Technology

PI FU CTIO S
resistor divider from the auxiliary output. To synchronize
with an external clock using the PLL, apply a CMOS
compatible clock with a frequency between 250kHz and
850kHz. To select pulse-skipping operation at light loads,
tie this pin to V
continuous operation, which allows the inductor current to
reverse. When synchronized to an external clock, pulse-
skipping operation is enabled at light loads.
BG1/BG2 (Pins 19, 13/Pins 22, 16): Bottom (NMOS) Gate
Drive Output. These pins drive the gates of the external N-
channel MOSFETs. These pins have an output swing from
PGND to SENSE
SENSE1
Input to Differential Current Comparator. Also powers the
gate drivers. Normally connected to the source of the ex-
ternal P-channel MOSFET.
FU CTIO AL DIAGRA
U
U
+
/SENSE2
U
U
+
IN
.
. Grounding this pin selects forced
+
U
(Pins 21, 11/Pins 24, 14): Positive
SYNC/FCB
RUN/SS
PLLLPF
UNDERVOLTAGE
LOCKOUT
0.6V
0.7µA
W
–
+
SYNC DETECT
CONTROLLED
OSCILLATOR
VOLTAGE
FCB
V
(Common Circuitry)
IN
EXTSS
REFERENCE
VOLTAGE
CLK1
CLK2
SHDN
FCB
t
SEC
C
VIN
= 1ms
DETECTOR
0.54V
R
0.6V
V
PHASE
VIN
REF
V
V
FB1
FB2
V
(TO CONTROLLER 1, 2)
IN
SLOPE
SW1/SW2 (Pins 22, 10/Pins 1, 13): Switch Node Connec-
tion to Inductor. Also the negative input to differential peak
current comparator and an input to the reverse current com-
parator. Normally connected to the drain of the external P-
channel MOSFETs, the drain of the external N-channel
MOSFET, and the inductor.
IPRG1/IPRG2 (Pins 23, 2/Pins 2, 5): Three-State Pins to
Select Maximum Peak Sense Voltage Threshold. These pins
select the maximum allowed voltage drop between the
SENSE
across the external P-channel MOSFET) for each channel.
Tie to V
respectively.
V
the remotely sensed feedback voltage for its controller from
an external resistor divider across the output.
COMP
–
+
+
–
FB1
+
–
/V
FB2
IN
+
and SW pins (i.e., the maximum allowed drop
, GND or float to select 345mV, 167mV, or 240mV
(Pins 24, 7/Pins 3, 10): Feedback Pins. Receives
UV1
UV2
SLOPE1
SLOPE2
OV1
INTSS
SHDN
OV2
PGOOD
37362 FD
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LTC3736-2
37362fa
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