LTC3407-3
5
34073fb
Load Regulation Load Regulation Line Regulation
PIN FUNCTIONS
V
OUT1
(Pin 1): Output Voltage Feedback Pin for Channel
1. An internal resistive divider divides the output voltage
down for comparison to the internal reference voltage.
RUN1 (Pin 2): Regulator 1 Enable. Forcing this pin to
V
IN
enables regulator 1, while forcing it to GND causes
regulator 1 to shut down. Do not fl oat this pin.
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. 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 operation
of the device. When tied to V
IN
or GND, Burst Mode opera-
tion or pulse-skipping mode is selected, respectively. The
oscillation frequency can be synchronized to an external
oscillator applied to this pin and pulse-skipping mode is
automatically selected. Do not fl oat this pin.
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 falls below
–8.5% of regulation and goes high after 117ms 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
regulator 2 to shut down. Do not fl oat this pin.
V
OUT2
(Pin 10): Output Voltage Feedback Pin for Channel 2.
An internal resistive divider divides the output voltage down
for comparison to the internal reference voltage.
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.
LOAD CURRENT (mA)
1
V
OUT
ERROR (%)
4
3
2
1
0
–1
–2
–3
–4
10 100 1000
34073 G12
V
IN
= 3.6V, V
OUT
= 1.8V
NO LOAD ON OTHER CHANNEL
Burst Mode OPERATION
PULSE-SKIPPING
MODE
LOAD CURRENT (mA)
1
0
V
OUT
ERROR (%)
2
4
10 100 1000
34073 G13
–2
–1
1
3
–3
–4
V
IN
= 5V, V
OUT
= 3.3V
NO LOAD ON OTHER CHANNEL
Burst Mode OPERATION
PULSE-SKIPPING
MODE
V
IN
(V)
2
V
OUT
ERROR (%)
–0.20
0
0.20
0.40
6
34073 G15
–0.40
–0.60
–1.00
–0.80
3
4
5
0.80
0.60
V
OUT
= 1.8V
I
OUT
= 200mA
TYPICAL PERFORMANCE CHARACTERISTICS
T
A
= 25°C unless otherwise specifi ed.
