LTC3118_15 Datasheet, PDF (35/38 Pages) Linear Technology – 18V, 2A Buck-Boost DC/DC Converter with Low-Loss Dual Input PowerPath

LTC3118
Typical Applications
Dual Battery System to 3.3V V_OUT, Runs from Lead Acid (Priority) When Present
Automatic Burst Mode Operation
3.3µH
10.5V TO 14.5V
+
LEAD ACID
BATTERY
0.1µF
768k
22µF
100k
V_IN1 SW1 BST1
RUN1
PGND
0.1µF
BST2 SW2 V_OUT
FB
GND
47nF
47nF
3V TO 16.5V
STACK OF 3-10 NiMH
OR ALKALINE BATTERIES
–
CM1
CM2
CP1
CP2
10nF
10nF
CN2
CN1
301k
22µF
200k
V_IN2
RUN2
PGND
LTC3118
VC
V1GD
V2GD
PGD
V_CC
SEL
MODE
3118 TA04a
3.3V UP TO 2.5A, V_IN > 4.5V
232k
100µF
PGND
100k
47pF
18.2k
3.9nF
POWER GOOD
INDICATORS
4.7µF
Efficiency vs Load Current: V_IN1 = 5V,
V_IN2 = 12V, V_OUT = 3.3V
100
90 _BURST
80
70
60
50
40
PWM
30
20
10
0
0.0001 0.001 0.01 0.1
V_IN1
V_IN2
1
10
LOAD CURRENT (A)
3118 TA04b
3.3V_OUT
TRANSIENT
200mV/DIV
INDUCTOR
CURRENT
1A/DIV
LOAD CURRENT
1A/DIV
VC
200mV/DIV
100mA to 1A Load Step, V_IN = 12V,
V_OUT = 3.3V, Auto Burst Mode
100µs/DIV
3118 TA04c
For more information www.linear.com/LTC3118
3118f
35