LTC3608 Datasheet, PDF (21/24 Pages) Linear Technology – 18V, 8A Monolithic Synchronous Step-Down DC/DC Converter

LTC3608
TYPICAL APPLICATIONS
5V to 18V Input to 1.2V/8A at 550kHz
PGND
INTV_CC
C_VCC
4.7μF
6.3V
SW
R_F1
1Ω
C_F
0.47μF
25V
40 39 38 37 36 35 34 33 32 31 30 29 28 27
V_IN2
EXTV_CC
C4
0.01μF
SGND
V_OUT
1.2V AT
8A
C5
22μF
6.3V
(OPTIONAL)
GND
C_OUT1 +
100μF
×2
L1
0.5μH
V_IN
5V TO 18V
V_IN
GND
C_IN
C6 +
10μF
10μF
25V
35V
3×
(OPTIONAL)
41 _SW
42 _SW
43 _SW
44 _SW
45 _SW
46 _SW
47 _SW
48
PV_IN
49 _PVIN
50 _PVIN
51 _PVIN
52 _PVIN
LTC3608
SGND ²⁶
NC ²⁵
R1
30k
NC ²⁴
1%
V_FB ²³
I_ON ²²
21
NC
SGND ²⁰
FCB ¹⁹
I_TH ¹⁸
V_RNG ¹⁷
PGOOD ¹⁶
SGND ¹⁵
1 2 3 4 5 6 7 8 9 10 11 12 13 14
C5: TAIYO YUDEN JMK316BJ226ML-T
C_IN: TAIYO YUDEN TMK432BJ106MM
C_OUT1: TDKC4532X5R107M
L1: CDEP85NP-R50MC-125
KEEP POWER GROUND AND SIGNAL GROUND SEPARATE.
CONNECT AT ONE POINT.
= PGND
INTV_CC
D_B
CMDSH-3
C_B1
0.22μF
C_SS
0.1μF
R_SS1
510k
V_IN
(OPTIONAL)
C1
(OPTIONAL) ^RON
187k
1%
R2
30.1k
1%
C_ON
0.01μF
(OPTIONAL)
(OPTIONAL)
C2
V_OUT
V_IN
R5
7.68k
C_C1
1500pF
R_PG1
100k
INTV_CC
V_OUT
R_VON
0.1μF (OPTIONAL)
C_C2
100pF
SGND
C_VON
V_OUT
3608 TA03
= SGND
Transient Response
I_L
5A/DIV
V_OUT
200mV/DIV
200mV
LOAD STEP 1A-8A
V_IN = 12V
V_OUT = 1.2V
FCB = 0V
3608 TA03a
Efficiency vs Load Current
90
V_IN = 12V
85 ^{FREQ = 550kHz}
80
75
70
DCM
OCM
65
60
55
50
100
1000
1000
LOAD CURRENT (A)
10000
3608 TA03b
3608fa
21