LTC3407-4 Datasheet, PDF (5/16 Pages) Linear Technology – Dual Synchronous, 800mA, 2.25MHz Step-Down DC/DC Regulator

TYPICAL PERFOR A CE CHARACTERISTICS
LTC3407-4
Efficiency vs Load Current
100
90
V_IN = 3.6V
V_IN = 2.7V
80
V_IN = 4.2V
70
60
50
40
30
20
V_OUT = 1.2V
10 Burst Mode OPERATION
NO LOAD ON OTHER CHANNEL
0
1
10
100
LOAD CURRENT (mA)
1000
34074 G13
Efficiency vs Load Current
100
90
V_IN = 3.6V
V_IN = 2.7V
80
V_IN = 4.2V
70
V_OUT = 1.5V
Burst Mode OPERATION
NO LOAD ON OTHER CHANNEL
60
1
10
100
LOAD CURRENT (mA)
1000
34074 G14
Line Regulation
0.8
V_OUT = 1.8V
0.6 ^IOUT ^{= 200mA}
T_A = 25°C
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
2
3
4
V_IN (V)
5
6
34074 G15
PI FU CTIO S
V_FB1 (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 V_IN
enables regulator 1, while forcing it to GND causes regu-
lator 1 to shut down. This pin must be driven; do not float.
V_IN (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 V_IN to GND.
GND (Pin 5): Ground. Connect to the (–) terminal of C_OUT,
and (–) terminal of C_IN.
MODE/SYNC (Pin 6): Combination Mode Selection and
Oscillator Synchronization. This pin controls the operation
of the device. When tied to V_IN or GND, Burst Mode
operation or pulse skipping mode is selected, respec-
tively. Do not float this pin. The oscillation frequency can
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 V_IN 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 2¹⁶ of clock
cycles when both channels are within regulation.
RUN2 (Pin 9): Regulator 2 Enable. Forcing this pin to V_IN
enables regulator 2, while forcing it to GND causes regu-
lator 2 to shut down. This pin must be driven; do not float.
V_FB2 (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 C_OUT, and (–) terminal of C_IN. Must be
connected to electrical ground on PCB.
34074f
5