LTC3118_15 Datasheet, PDF (34/38 Pages) Linear Technology – 18V, 2A Buck-Boost DC/DC Converter with Low-Loss Dual Input PowerPath

LTC3118
Typical Applications
12V Wall Adapter (When Present) or 2-Cell Li-Ion to 12V V_OUT Regulator with Automatic Burst Mode Operation
6.8µH
6V TO 8.2V
+
+ ^Li-Ion
22µF
0.1µF
402k
100k
V_IN1 SW1 BST1
RUN1
PGND
0.1µF
BST2 SW2 V_OUT
FB
GND
47nF
47nF
10nF
10V TO 14V
+
12V WALL
ADAPTER
100µF
CM1
CM2
CP1
CP2
10nF
CN2
CN1
750k
100k
V_IN2
RUN2
PGND
LTC3118
VC
V1GD
V2GD
PGD
V_CC
SEL
MODE
3118 TA03a
1100k
12V AT 800mA
100µF
PGND
100k
22pF
60.4k
1.2nF
POWER GOOD
INDICATORS
4.7µF
Efficiency vs Load Current: V_IN1 = 7V,
V_IN2 = 12V, V_OUT = 12V
100
90 ^BURST
80
70
60
50
PWM
40
30
20
10
0
0.0001 0.001 0.01 0.1
V_IN1
V_IN2
1
10
LOAD CURRENT (A)
3118 TA03b
12V_IN2 to 6V_IN1 SEL Pin Switchover
with V_OUT = 12V and 800mA Load
12V_OUT
TRANSIENT
500mV/DIV
INDUCTOR
1A
2A
CURRENT
1A/DIV
SW1
10V/DIV
SEL
500µs/DIV
3118 TA03c
12V_IN2 Inductive Cable Insertion
with V_OUT = 12V and 800mA Load
12V_OUT
TRANSIENT
500mV/DIV
V_IN2
5V/DIV
V_IN1
5V/DIV
CABLE
INSERTION
INDUCTOR
CURRENT
2A/DIV
V_OUT = 12V
V_IN2 = 12V
V_IN1 = 6V
SWITCHOVER TO V_IN2
100µs/DIV
3118 TA03d
3118f
34
For more information www.linear.com/LTC3118