LTC3836_15 Datasheet, PDF (26/30 Pages) Linear Technology – Dual 2-Phase, No RSENSETM Low VIN Synchronous Controller

LTC3836
TYPICAL APPLICATIONS
C_FFW1, 120pF
R_FB1B, 66.5k
R_TRACKB, 68.1k
500kHz
V_IN
2.75V TO
4.2V
C_IN
X3
R_FB1A, 61.9k
R_TRACKA, 61.9k
C_ITH1A, 100pF
C_ITH1, 2700pF
R_ITH1, 1.37k
C_PLLLPF, 0.015RF _{RPLLLPF, 15k}
C_SS, 10nF
C_ITH2A, 100pF
C_VIN, 10RF
R_VIN, 10<
L1, L2: TOKO 0.47RF FDV0630-R47M=P3
C_IN: 22RF X3, 6.3V, X5R
C_OUT: AVX CORECAP 560RF, 2.5V
NPV V567M002 R003
M1, M2, M3, M4: SILICONIX Si7882DP
LTC3836EUFD
1
V_FB1
24
BOOST1
D_B1
C_B1, 0.22RF
7
TRACK/SS2
26
SW1
SENSE1^{+ 25}
M1
2
I_TH1
27
IPRG1
4
PLLLPF
21
SYNC/FCB
17
RUN/SS
5
SGND
6
10 ^VIN
PGOOD
3 _IPRG2
9 _ITH2
8 _VFB2
20
TG1
22
BG1
23
PGND
29
PGND
19
PGND
14
PGND
15
BG2 ₁₈
TG2
SENSE2^{+ 12}
SW2 ¹¹
BOOST2 ¹³
M4
C_B2, 0.22RF
N/C N/C
D_B2
16 28
M2
M3
L1
D1
B320A
C_OUT
V_OUT
1.25V
20A
D2
B320A
L2
3836 F17
Figure 17a. Single Output, High Current Application with External Frequency Synchronization
100
V_IN = 2.7V
90
80
70
V_IN = 3.6V
60
50
V_IN = 4.2V
40
30
20
10
100
1000 10000
LOAD CURRENT (mA)
100000
3836 F17b
Figure 17b. Efficiency vs Load Current
26
V_OUT
200mV/DIV
AC COUPLED
I_L1
5A/DIV
I_L2
5A/DIV
I_LOAD
5A/DIV
40μs/DIV
V_IN = 3.3V
V_OUT = 1.25V
I_LOAD = 10A TO 15A
3836 F17c
Figure 17c. Load Step
3836fb