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LTC3407-2
5
34072fa
VFB1 (Pin 1): Output Feedback. Receives the feedback
voltage from the external resistive divider across the
output. Nominal voltage for this pin is 0.6V.
RUN1 (Pin 2): Regulator 1 Enable. Forcing this pin to VIN
enables regulator 1, while forcing it to GND causes regu-
lator 1 to shut down.
VIN (Pin 3): Main Power Supply. Must be closely decoupled
to GND.
SW1 (Pin 4): Regulator 1 Switch Node Connection to the
Inductor. This pin swings from VIN to GND.
GND (Pin 5): Main Ground. Connect to the (–) terminal of
COUT, and (–) terminal of CIN.
MODE/SYNC (Pin 6): Combination Mode Selection and
Oscillator Synchronization. This pin controls the operation
of the device. When tied to VIN or GND, Burst Mode
operation or pulse skipping mode is selected, respec-
tively. Do not float this pin. The oscillation frequency can
UU
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PI FU CTIO S
be syncronized to an external oscillator applied to this pin
and pulse skipping mode is automatically selected.
SW2 (Pin 7): Regulator 2 Switch Node Connection to the
Inductor. This pin swings from VIN to GND.
POR (Pin 8): Power-On Reset . This common-drain logic
output is pulled to GND when the output voltage is not
within
±8.5% of regulation and goes high after 117ms
when both channels are within regulation.
RUN2 (Pin 9): Output Feedback. Forcing this pin to VIN
enables regulator 2, while forcing it to GND causes regu-
lator 2 to shut down.
VFB2 (Pin 10): Output Feedback. Receives the feedback
voltage from the external resistive divider across the
output. Nominal voltage for this pin is 0.6V.
Exposed Pad (GND) (Pin 11): Power Ground. Connect to
the (–) terminal of COUT, and (–) terminal of CIN. Must be
connected to electrical ground on PCB.
TYPICAL PERFOR A CE CHARACTERISTICS
UW
VIN (V)
2
V
OUT
ERROR
(%)
0.5
0.4
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
4
6
3407 G15
35
VOUT = 1.8V
IOUT = 200mA
TA = 25°C
LOAD CURRENT (mA)
1
EFFICIENCY
(%)
100
95
90
85
80
75
70
65
60
10
100
1000
3407 G13
2.7V
4.2V
VOUT = 1.2V
Burst Mode OPERATION
NO LOAD ON OTHER CHANNEL
CIRCUIT OF FIGURE 1
LOAD CURRENT (mA)
1
EFFICIENCY
(%)
100
95
90
85
80
75
70
65
60
10
100
1000
3407 G14
2.7V
4.2V
VOUT = 1.5V
Burst Mode OPERATION
NO LOAD ON OTHER CHANNEL
CIRCUIT OF FIGURE 1
3.6V
Efficiency vs Load Current
Line Regulation
TA = 25°C unless other wise specified.