ir3500a International Rectifier Corp., ir3500a Datasheet - Page 41

• Manufacturer Part Number: ir3500a
• Description: Xphase3 Vr11.0 & Amd Pvid Control Ic
• Manufacturer: International Rectifier Corp.

VOLTAGE LOOP COMPENSATION
Type III compensation is used for the converter with only ceramic output capacitors. The crossover frequency and
phase margin of the voltage loop can be estimated as follows.
Choose R
Choose
Choose the desired crossover frequency fc (=150kHz) around fc1 estimated above, and calculate
Choose R
Choose C
θ
C
C
C
R
R
R
f
C
C
DRP
CP
DRP
FB
CP
HOTSET
1
1
=
=
=
=
=
=
=
90
10
2
4
2 (
(
1
R
π
π
R
Page 41 of 47
−
π
=
R
∗
FB
FB
∗
∗
FB
A
FB
CP1
FB
∗
C
(
R
f
∗
+
tan(
L
R
1
C
f
1
=13.7k .
CP
E
C
R
= 1.65k , and calculate R
R
R
E
TMAX
=
=47pF to reduce high frequency noise.
∗
n
DRP
)
L
FB
∗
∗
2
R
. 0
∗
_
2
3
G
C
1
∗
FB
R
MAX
R
) 5
)
∗
CS
L
E
∗
O
+
DRP
1
V
R
E
∗
C
I
=
FB
=
R
∗
∗
180
FB
*
π
10
HOTSET
C
G
R
4
=
π
=
E
CS
FB
∗
=
2
3
∗
∗
. 1 (
1
∗
150
R
=
63
∗
6 .
(
2
65
. 1
100
FB
R
)
. 1
°
65
( *
LE
*
*
65
∗
10
10
*
VCCL
5
*
1
*
10
=
3
10
3
=
10
6
+
13
∗
2
. 6
−
3
. 1
*
2 (
. 1
9
π
3
65
7 .
=
. 0
*
* 1
/
* 1
π
∗
) 6
−
. 1
∗
. 0
91
*
DRP
(
10
∗
10
10
10
. 1
62
10
64
∗
150
*
3
) 6
(
3
3
10
3
)
k
22
*
∗
.
∗
Ω
=
10
*
22
−
=
4
*
3
10
4
7 .
−
10
8 .
(
*
3
142
*
3
10
*
nF
)
10
−
2
6
34
∗
−
−
*
+
, choose C
9
6
(
62
100
=
)
=
931
∗
)
. 6
. 6
2
34
1
0 .
58
*
=
65
6 .
* )
10
nF
3
∗
k
*
5 .
. 1
Ω
7 (
−
10
9
nF
65
, choose R
/
−
FB
3
12
) 6
*
. 1
, choose C
10
=4.7nF.
∗
) 6
, choose C
(
3
22
=
∗
*
0 (
. 3
10
5 .
63
DRP
−
*
6
k
CP
10
∗
Ω
=6.65k .
DRP
62
=3.3nF.
, choose R
−
3
)
=2.2nF.
∗
/
. 1
) 6
65
=
*
165
10
HOTSET1
3
kHz
*
5
=
July 3, 2008
13
=3.65k .
9 .
IR3500A
k
Ω