LTC3546 Datasheet, PDF (24/28 Pages) Linear Technology – Dual Synchronous, 3A/1A or 2A/2A Confi gurable Step-Down DC/DC Regulator

LTC3546
APPLICATIONS INFORMATION
V_IN
2.25V TO 5.5V
V_OUT2
1.8V, 2A
C_OUT2
47μF
C_IN
22μF
R5
100k
L2
0.56μH
C_FF2
100pF
V_IN1 V_CCA V_CCD V_IN2
SYNC/MODE
PGOOD2
PGOOD1
SW2A
SW2B
SW1
SW1D
R6
100k
L1
0.56μH
C_FF1
100pF
R3 _R4
60.4k _30.1k
V_IN
RUN2 _LTC3546 RUN1
V_FB2
V_FB1
V_IN
R_ITH2
13k
C_ITH2
1000pF
BMC2
BMC1
TRACK/SS2 TRACK/SS1
PHASE
FREQ
I_TH2
I_TH1
PGND2 GNDA PGND1
EXPOSED PAD
V_IN
V_IN
R_ITH1
13k
C_ITH1
1000pF
R2 ^R1
30.1k ^30.1k
R_FREQ
143k
Figure 7. Typical Schematic for 2A/2A Regulator
V_OUT1
1.2V, 2A
C_OUT1
47μF
3546 F07
5V V_IN
V_OUT2
2.5V/2A
C5
22μF, X5R
R7
100k
R8
100k
C1
22μF, X5R
s2
R1
316k
R3
100k
R9
90.9k
L1
1.0μH
C6
10pF
R6
5.1k
C4
470pF
V_CC
RUN2
PGOOD2
SYNC/MODE
RUN1
PGOOD1
LTC3546
SW2A
SW2B
V_FB2
FREQ
I_TH2
TRACK/SS2
SW1
SW1D
V_FB1
PHASE
I_TH1
TRACK/SS1
C9
0.1μF
BMC2 GND BMC1
3546 F08
L2
1.0μH
C7
R2
33pF
200k
R4
100k
C8
0.1μF
R5
8.2k
C3
330pF
f_SW = 2.25MHz
Figure 8. A 2.25MHz Fixed Frequency 2A/2A Regulator
V_OUT1
C2 ^1.8V/2A
22μF, X5R
s2
3546fb
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