LTC3826_15 Datasheet, PDF (31/36 Pages) Linear Technology – 30A IQ, Dual, 2-Phase Synchronous Step-Down Controller

LTC3826
TYPICAL APPLICATIONS
C_SS1
0.01μF
C_ITH1A
180pF
39pF
C_ITH1
560pF
R_ITH1
34k
R_A1
68.1k
R_B1
215k
C1
470pF
R_A2
22.1k
C_ITH2
330pF
R_ITH2
52.3k
C_ITH2A
56pF
C_SS2
0.01μF
C2
470pF
R_B2
215k
LTC3826
I_TH1
TRACK/SS1
PGOOD2
V_FB1
PGOOD1
SENSE1⁺
TG1
SENSE1^–
SW1
PLLLPF
PHASMD
CLKOUT
PLLIN/MODE
SGND
RUN1
RUN2
BOOST1
BG1
V_IN
PGND
EXTV_CC
SENSE2^–
INTV_CC
SENSE2⁺
BG2
V_FB2
BOOST2
I_TH2
SW2
TRACK/SS2
TG2
FOLDDIS
39pF
100k
100k
C_B1 0.47μF
D1
C_INT2
4.7μF
D2
MTOP1 _L1
2.2μH
R_SNS1
12mΩ
MBOT1
C_OUT1
150μF
V_OUT1
3.3V
5A
V_IN
12V
C_IN1
10μF
C_IN2
10μF
MTOP2 L2
7.2μH
R_SNS2
15mΩ
MBOT2
V_OUT2
8.5V
C_{OUT2 3.5A}
150μF
MTOP1, MTOP2, MBOT1, MBOT2: Si7848DP
L1: CDEP105-2R2M
L2: CDEP105-7R2M
C_OUT1, C_OUT2 = SANYO 10TPD150M
3826 TA02
Efficiency vs Output Current
100
V_OUT = 3.3V
90
V_OUT = 8.5V
80
70
60
50
40
30
20
10
0
0.000001 0.00001 0.0001 0.001 0.01 0.1
OUTPUT CURRENT (A)
1 10
3826 F13a
Start-Up
V_OUT2, 2V/DIV
V_OUT1, 2V/DIV
3826 F13b
SW Node Waveform
SW1
5V/DIV
SW2
5V/DIV
3826 F13c
Figure 13. High Efficiency Dual 8.5V/3.3V Step-Down Converter
3826fc
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