Datasheet

LTC3714
23
3714f
applicaTions inForMaTion
C
C1
100pF
R
VP1
23k
R
VP2
185k
C
C1
2.2nF
C
SS
0.1µF
C
FB
100pF
C
ION
0.01µF
R
ON
330k
R
C
20k
R
RNG2
90.1k
R
RNG1
10k
3714 F08
R
PG
100k
R
F
1Ω
C
B
0.33µF
M1
IRF7811
D1
UPS840
L1
0.68µH
M2
IRF7811
×2
D
B
CMDSH-3
C
VCC
4.7µF
C
F
0.1µF
5V
C
IN
10F
25V
×3
V
IN
7V TO 24V
V
OUT
1.15V/15A
C
OUT
270µF
2V
×3
C
IN
: UNITED CHEMICON THCR70EIH226ZT
C
OUT
: PANASONIC EEFUE0D271
L1: SUMIDA CEP125-4712-T007
0.1µF
INTV
CC
R
SENSE
0.003Ω
9
10
11
12
13
14
19
21
22
20
23
24
15
16
8
7
6
5
4
3
2
1
28
27
26
25
18
17
VID2
RUN/SS
V
ON
PGOOD
V
RNG
I
TH
SGND
I
ON
V
FB
FCB
V
OSENSE
VID3
OPV
IN
OP
–
VID1
VID0
BOOST
TG
SW
SENSE
PGND
BG
INTV
CC
V
IN
EXTV
CC
VID4
OPOUT
OP
+
LTC3714
Figure 9. CPU Core Voltage Regulator with Active Voltage Positioning 1.15V/15A at 300kHz
Solving for this resistance value:
R
VP
=
V
OUT
ΔI
TH
(0.6V)g
m
ΔV
OUT
=
(1.15V)(1.08V)
(0.6V)(1.7mS)(60mV)
= 20.3k
The gain setting resistance R
VP
is implemented with two
resistors, R
VP1
connected from I
TH
to ground and R
VP2
connected from I
TH
to INTV
CC
. The parallel combination of
these resistors must equal R
VP
and their ratio determines
nominal value of the I
TH
pin voltage when the error ampli-
fier input is zero. To set the beginning of the load line at
the regulation point, the I
TH
pin voltage must be set to
correspond to zero output current. The relation between
voltage and the output current is:
I
TH(NOM)
=
12V
V
RNG
⎛
⎝
⎜
⎞
⎠
⎟
R
SENSE
I
OUT
–
1
2
ΔI
L
⎛
⎝
⎜
⎞
⎠
⎟
+ 0.75V
=
12V
0.5V
⎛
⎝
⎜
⎞
⎠
⎟
0.003Ω
( )
0A –
1
2
5.4A
⎛
⎝
⎜
⎞
⎠
⎟
+ 0.75V
=
0.55V