LTC3714 Linear, LTC3714 Datasheet - Page 21

• Manufacturer Part Number: LTC3714
• Description: Wide Operating Range / Step-Down Controller with Internal Op Amp
• Manufacturer: Linear

APPLICATIO S I FOR ATIO
Next, choose the synchronous MOSFET switch. Because
of the narrow duty cycle and large current, a single SO-8
MOSFET will have difficulty dissipating the power lost in
the switch. Choosing two IRF7811s (R
C
Tying V
range for a nominal value of 140mV with current limit
occurring at 186mV. To check if the current limit is
acceptable, assume a junction temperature of about 100 C
above a 50 C ambient with
RSS
V
SNS(NOM)
= 60pF) yields a nominal sense voltage of:
RNG
C
C
L1: SUMIDA CEP125-4712-T007
IN
OUT
: UNITED CHEMICON THCR70EIH226ZT
to INTV
: PANASONIC EEFUE0D271
0.1 F
2.2nF
= (15A)(0.5)(1.3)(0.013 ) = 127mV
C
C
C
C
SS
ION
C1
FB
100pF
0.01 F
Figure 8. CPU Core Voltage Regulator 1.15V/15A at 300kHz without Active Voltage Positioning
20k
R
U
CC
330k
C
R
ON
will set the current sense voltage
U
C
100pF
100k
R
C2
PG
150 C
10
11
12
13
14
19
21
22
20
23
24
15
16
9
VID2
RUN/SS
V
PGOOD
V
I
SGND
I
V
FCB
V
VID3
OPV
OP
TH
ON
ON
RNG
FB
OSENSE
W
= 1.6:
–
IN
LTC3714
DS(ON)
EXTV
INTV
BOOST
OPOUT
SENSE
PGND
VID1
VID0
VID4
OP
SW
V
BG
TG
CC
CC
IN
+
U
= 0.013 ,
8
7
6
5
4
3
2
1
28
27
26
25
18
17
5V
C
0.33 F
C
4.7 F
B
VCC
C
0.1 F
CMDSH-3
F
D
1
R
and double check the assumed T
B
F
P
T
I
BOT
LIMIT
J
= 50 C + (1.98W)(50 C/W) = 149 C
24
0 5 1 6 0 013
V
M1
IRF7811
M2
IRF7811
.
2
24
– .
1 15
V
186
.
0.68 H
L1
V
mV
D1
UPS840
.
20
3714 F08
2
A
2
1 6 0 013
J
.
2
1
in the MOSFET:
C
22 F
25V
C
270 F
2V
IN
OUT
3
5
5 4
.
.
LTC3714
A
V
7V TO 24V
V
1.15V
15A
IN
OUT
20
A
21
1 98
.
3714f
W