LTC3546_15 Datasheet, PDF (26/30 Pages) Linear Technology – Dual Synchronous, 3A/1A or 2A/2A Configurable Step-Down DC/DC Regulator

LTC3546
Applications Information
V_IN
2.25V TO 5.5V
V_OUT2
2.5V, 3A
C_OUT2
33µF
x2
C_IN
22µF
R5
100k
L2
0.56µH
C_FF2
100pF
V_IN
R3 _R4
95.3k _30.1k
V_IN
R_ITH2
13k
C_ITH2
1000pF
V_IN1 V_CCA V_CCD V_IN2
SYNC/MODE
PGOOD2
PGOOD1
SW2A
SW2B
SW1D
RUN2
V_FB2
LTC3546
SW1
RUN1
V_FB1
BMC2
BMC1
TRACK/SS2 TRACK/SS1
PHASE
FREQ
I_TH2
I_TH1
PGND2 GNDA PGND1
EXPOSED PAD
R6
100k
L1
1.2µH
C_FF1
100pF
V_IN
R2 ^R1
30.1k ^59k
V_IN
V_OUT1
1.8V, 1A
C_OUT1
22µF
R_ITH1
13k
C_ITH1
1000pF
R_FREQ
143k
3546 F09
Figure 9. Typical Schematic for 3A/1A Regulator
OUT1 Efficiency (Burst Mode Operation)
100
100
95
10
EFFICIENCY
90
1
85
0.1
80
0.01
POWER LOSS
75
0.001
70
0.001
0.01
0.1
LOAD CURRENT (A)
0.0001
1
3546 F09b
OUT2 Efficiency (Burst Mode Operation)
100
100
SW1D CONNECTED TO SW2
V_IN = 3.6V
95 VOUT = 2.5V
10
90
EFFICIENCY
1
85
0.1
80
0.01
POWER LOSS
75
0.001
70
0.001
0.01
0.1
1
LOAD CURRENT (A)
0.0001
10
3546 F09c
3546fc
26
For more information www.linear.com/3546