LTC3548 Datasheet, PDF (14/16 Pages) Linear Technology – Dual Synchronous, 400mA/800mA, 2.25MHz Step-Down DC/DC Regulator

LTC3548
TYPICAL APPLICATIO S
1mm Profile Core and I/O Supplies
V_IN = 3.6V
TO 5.5V
C1*
10µF
V_OUT2 = 3.3V
AT 400mA
L2
4.7µH
C5, 68pF
RUN2 V_IN RUN1
MODE/SYNC
POR
LTC3548
SW2
SW1
R5
100k
POWER-ON
RESET
L1
2.2µH
C4, 33pF
C3
4.7µF
R4
887k R3
196k
V_FB2
GND
V_FB1
R2
R1 604k
301k
V_OUT1 = 1.8V
AT 800mA
C2
10µF
C1, C2: MURATA GRM219R60J106KE19
C3: MURATA GRM219R60J475KE19
L1: COILTRONICS LPO3310-222MX
L2: COILTRONICS LPO3310-472MX
*IF C1 IS GREATER THAN 3" FROM POWER SOURCE,
ADDITIONAL CAPACITANCE MAY BE REQUIRED.
3548 TA07
Efficiency vs Load Current
100
95
3.3V
90
85
1.8V
80
75
70
65
V_IN = 5V
Burst Mode OPERATION
NO LOAD ON OTHER CHANNEL
60
1
10
100
LOAD CURRENT (mA)
1000
3548 TA08
3548f
14