LTC3548-1 Datasheet, PDF (5/16 Pages) Linear Technology – Dual Synchronous, Fixed Output 2.25MHz Step-Down DC/DC Regulator

LTC3548-1
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C unless otherwise specified.
Efficiency vs Load Current
100
95
90 ^{VIN = 3.6V}
V_IN = 2.7V
85
V_IN = 4.2V
80
75
70
65
V_OUT1 = 1.8V
NO LOAD ON OTHER CHANNEL
CIRCUIT OF FIGURE 3
60
1
10
100
1000
LOAD CURRENT (mA)
3548-1 G16
Efficiency vs Load Current
100
95
V_IN = 3.6V V_IN = 2.7V
90
85
80
V_IN = 4.2V
75
70
65
V_OUT2 = 1.575V
NO LOAD ON OTHER CHANNEL
60
CIRCUIT OF FIGURE 3
1
10
100
1000
LOAD CURRENT (mA)
3548-1 G17
PIN FUNCTIONS
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. Connect to the (–) terminal of C_OUT
and (–) terminal of C_IN (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 float.
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 float.
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).
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