LTC3101
TYPICAL APPLICATIONS
2 AA Cell/USB/Wall Adapter Power Supply with Six Output Rails and Pushbutton On/Off
V
= 3.3V
OUT3
300mA FOR V ≥ 1.8V
IN
+
C3
10μF
C4
10μF
800mA FOR V ≥ 3V
IN
2 AA
CELLS
R8
1M
L3
4.7μH
R7
BAT1 BAT2 SW3A SW3B OUT3
221k
USB POWER
USB1
USB2
FB3
HSO
Hot Swap OUTPUT
4.3V TO 5.5V
C5
10μF
3.3V
WALL ADAPTER
4.0V TO 5.5V
C8
100mA
4.7μF
TRACKING OUTPUT
200mA
MAX
ENA3
ENA2
ENA1
C7
4.7μF
0.22μF
C
RS
1.8V
LDO
50mA
LTC3101
C6
4.7μF
L2
ON/OFF
4.7μH
V
OUT2
SW2
FB2
1.8V
PWRKEY
C2
10μF
C9
22pF
R6
221k
350mA
V
OUT1
μP
R5
110k
L1
4.7μH
R1
R2
V
OUT1
50k 50k
1.5V
SW1
FB1
PBSTAT
PWRON
RESET
PWM
C1
10μF
R4
221k
C10
22pF
350mA
R3
147k
GND
C1-C5: MURATA GRM31CR71A106KA01
L1, L2: TAIYO YUDEN NR3010T4R7M
L3: COILCRAFT LPS4018-472ML
3101 TA02a
Buck-Boost Converter Efficiency
vs Load Current
Buck Converter Efficiency
Waveforms During Power-Up
vs Load Current, VBAT = 3V
100
90
100
90
PWRKEY
5V/DIV
Burst Mode
OPERATION
Burst Mode
OPERATION
V
V
V
2V/DIV
80
70
60
80
70
60
OUT1
2V/DIV
5V/DIV
OUT2
OUT3
PWM MODE
PWM MODE
HSO 5V/DIV
50
40
50
40
C
100mV/DIV
RS
3101 TA02b
5ms/DIV
30
20
10
0
30
20
10
0
V
BAT
V
BAT
= 2V
BUCK1 (1.5V)
BUCK2 (1.8V)
= 3V
1
100
10
LOAD CURRENT (mA)
1000
1
100
10
LOAD CURRENT (mA)
1000
3101 TA02c
3101 TA02d
3101f
28
Linear [ Linear ]
