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LTC3407AIDD Datasheet, PDF (5/16 Pages) Linear Integrated Systems – Dual Synchronous, 600mA, 1.5MHz Step-Down DC/DC Regulator
TYPICAL PERFORMANCE CHARACTERISTICS
LTC3407
Efficiency vs Load Current
100
95
3.3V
2.7V
90
85
4.2V
80
75
70
65
60
1
VOUT = 1.2V Burst Mode OPERATION
CIRCUIT OF FIGURE 1
10
100
LOAD CURRENT (mA)
1000
3407 G13
Efficiency vs Load Current
100
95
3.3V
2.7V
90
85
4.2V
80
75
70
65
60
1
VOUT = 1.5V Burst Mode OPERATION
CIRCUIT OF FIGURE 1
10
100
LOAD CURRENT (mA)
1000
3407 G14
Line Regulation
0.5
0.4
VOUT = 1.8V
IOUT = 200mA
0.3 TA = 25°C
0.2
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
2
3
4
VIN (V)
5
6
3407 G15
PIN FUNCTIONS
VFB1 (Pin 1): Output Feedback. Receives the feedback volt-
age 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 regulator
1 to shut down. This pin must be driven; do not float.
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): Ground. This pin is not connected internally.
Connect to PCB ground for shielding.
MODE/SYNC (Pin 6): Combination Mode Selection and
Oscillator Synchronization. This pin controls the opera-
tion of the device. When tied to VIN or GND, Burst Mode
operation or pulse-skipping mode is selected, respectively.
Do not float this pin. The oscillation frequency can be
synchronized 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 175ms
when both channels are within regulation.
RUN2 (Pin 9): Regulator 2 Enable. Forcing this pin to VIN
enables regulator 2, while forcing it to GND causes regulator
2 to shut down. This pin must be driven; do not float.
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
soldered to electrical ground on PCB.
3407fa
5