LTC1909-8 Datasheet, PDF (27/32 Pages) Linear Technology – Wide Operating Range,No RSENSE TM Step-Down DC/DC Controller with SMBus Programming

APPLICATIO S I FOR ATIO
SEL
SDA
SCL
VRON
C_SS
0.1µF
1
28
RUN/SS BOOST
R_RNG1
4.99k
R_RNG2
45.3k
R_PG
100k
2
V_ON
3
PGOOD
27
TG
26
SW
R_VP2
40.2k
R_VP1
12.4k
4
V_RNG
5
FCB
SENSE^{+ 25}
24
PGND
C_C1
180pF
6
I_TH
23
BG
LTC1909-8
7
22
SGND INTV_CC
C_FB 100pF
8
I_ON
9
V_FB
21
V_IN
20
EXTV_CC
5V
10
SEL
19
V_CC
11
SDA
18
GND
12
SCL
17
FB
R_ON
330k
13
16
VRON V_OSENSE
14
15
PGTMR CPUON
D_B
CMDSH-3
C_B
0.33µF
C_VCC
4.7µF
R_F
1Ω
C_F
0.1µF
LTC1909-8
C_IN
22µF
50V
×3
M1
IRF7811A
L1
1µH
M2
IRF7811A
×2
D1
B540
V_IN
7V TO 24V
V_OUT
1.5V
15A
+ ^COUT
270µF
2V
×5
R_SENSE
0.003Ω
19098 F08
C_IN: UNITED CHEMICON THCR70EIH226ZT
C_OUT: CORNELL DUBILIER ESRE271M02B
L1: SUMIDA CEP125-IR0MC-H
Figure 8. CPU Core Voltage Regulator with Active Voltage Positioning 1.5V/15A at 300kHz
V_OUT
100mV/DIV
1.5V
V_OUT
100mV/DIV
1.5V
I_L
10A/DIV
C_OUT = 5 × 270µF
V_IN = 15V
FIGURE 7 CIRCUIT
20µs/DIV
3711 F09
Figure 9. Normal Transient Response
I_L
10A/DIV
C_OUT = 3 × 270µF
V_IN = 15V
FIGURE 8 CIRCUIT
20µs/DIV
3711 F10
Figure 10. Transient Response with Active Voltage Positioning
19098f
27