LTC3736 LINER [Linear Technology], LTC3736 Datasheet - Page 7

• Manufacturer Part Number: LTC3736
• Description: Dual 2-Phase, No RSENSE Synchronous Controller with Output Tracking
• Manufacturer: LINER [Linear Technology]

PI FU CTIO S
For auxiliary winding applications, connect to a 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 Burst Mode operation at light loads, tie this pin to V
Grounding this pin selects forced 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
+
.
+
U
(Pins 21, 11/Pins 24, 14): Positive
SYNC/FCB
RUN/SS
PLLLPF
IPRG1
IPRG2
UNDERVOLTAGE
LOCKOUT
(UF/GN Package)
0.6V
0.7 A
–
+
SENSE VOLTAGE
BURST DEFEAT/
SYNC DETECT
CONTROLLED
CONTROLLED
OSCILLATOR
OSCILLATOR
MAXIMUM
VOLTAGE
VOLTAGE
W
SELECT
FCB
V
IN
EXTSS
REFERENCE
VOLTAGE
(Common Circuitry)
CLK1
CLK2
SHDN
FCB
BURSTDIS
t
SEC
IPROG1
IPROG2
C
VIN
= 1ms
DETECTOR
R
0.6V
V
PHASE
VIN
REF
IN
V
(TO CONTROLLER 1, 2)
0.54V
IN
.
SLOPE
COMP
V
V
–
+
FB1
FB2
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
comparator. Normally connected to the drain of the exter-
nal 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.
FB1
–
+
+
–
/V
FB2
+
IN
SLOPE1
SLOPE2
and SW pins (i.e., the maximum allowed drop
, GND or float to select 204mV, 85mV or 125mV
(Pins 24, 7/Pins 3, 10): Feedback Pins. Receives
INTSS
UV1
UV2
OV1
SHDN
OV2
PGOOD
3736 FD
LTC3736
7
3736f