LTC3548-1
5
35481fc
TYPICAL PERFORMANCE CHARACTERISTICS
Effi ciency vs Load Current Effi ciency vs Load Current
T
A
= 25°C unless otherwise specifi ed.
LOAD CURRENT (mA)
1
80
EFFICIENCY (%)
90
100
10 100 1000
3548-1 G16
70
75
85
95
65
60
V
IN
= 2.7V
V
IN
= 4.2V
V
IN
= 3.6V
V
OUT1
= 1.8V
NO LOAD ON OTHER CHANNEL
CIRCUIT OF FIGURE 3
LOAD CURRENT (mA)
1
80
EFFICIENCY (%)
90
100
10 100 1000
3548-1 G17
70
75
85
95
65
60
V
IN
= 2.7V
V
IN
= 4.2V
V
IN
= 3.6V
V
OUT2
= 1.575V
NO LOAD ON OTHER CHANNEL
CIRCUIT OF FIGURE 3
V
FB1
(Pin 1): Output Feedback for Channel 1. Receives the
feedback voltage from internal resistive divider across the
output. Normal voltage for this pin is 0.6V.
V
OUT1
(Pin 2): Output Voltage Feedback Pin for Channel 1.
An internal resistive divider divides the output voltage down
for comparison to the internal reference voltage.
V
IN
(Pin 3): Input 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 inter-
nally. Connect to PCB ground for optimum shielding (see
Figure 4).
RUN2 (Pin 6): Regulator 2 Enable. Forcing this pin to V
IN
en-
ables regulator 2, while forcing it to GND causes regulator 2
to shut down. This pin must be driven; do not fl oat.
SW2 (Pin 7): Regulator 2 Switch Node Connection to the
Inductor. This pin swings from V
IN
to GND.
RUN1 (Pin 8): Regulator 1 Enable. Forcing this pin to V
IN
en-
ables regulator 1, while forcing it to GND causes regulator 1
to shut down. This pin must be driven; do not fl oat.
V
OUT2
(Pin 9): Output Voltage Feedback Pin for Channel 2.
An internal resistive divider divides the output voltage down
for comparison to the internal reference voltage.
V
FB2
(Pin 10): Output Feedback for Channel 2. Receives
the feedback voltage from internal resistive divider across
the output. Normal voltage for this pin is 0.6V.
Exposed Pad (GND) (Pin 11): Ground. Connect to the
(–) terminal of C
OUT
, and (–) terminal of C
IN
. Must be con-
nected to electrical ground on PCB (see Figure 4).
PIN FUNCTIONS
