ir3082pbf International Rectifier Corp., ir3082pbf Datasheet - Page 23

• Manufacturer Part Number: ir3082pbf
• Description: Xphase Amd Opterontm/athlon 64tm Control Ic
• Manufacturer: International Rectifier Corp.

If the over temperature setting voltage is higher than the phase delay setting voltage, VBIAS times RA
connect HOTSET pin between R
R
Bootstrap Capacitor C
Depending on the duty cycle and gate drive current of the phase IC, a 0.1uF to 1uF capacitor is needed for the
bootstrap circuit.
Decoupling Capacitors for Phase IC
0.1uF-1uF decoupling capacitors are required at VCC and VCCL pins of phase ICs.
VOLTAGE LOOP COMPENSATION
The adaptive voltage positioning (AVP is usually used in the computer applications to improve the transient
response and reduce the power loss at heavy load. Like current mode control, the adaptive voltage positioning loop
introduces extra zero to the voltage loop and splits the double poles of the power stage, which make the voltage
loop compensation much easier.
Resistors R
depends on the capacitors used. For the applications using Electrolytic, Polymer or AL-Polymer capacitors, type II
compensation shown in Figure 18 (a) is usually enough. While for the applications with only ceramic capacitors,
type III compensation shown in Figure 18 (b) is preferred.
PHASEx3
VO+
VDR P
Page 23 of 33
respectively. Pre-select R
FB
and R
RFB
RDRP
(a) Type II compensation
R
R
R
R
PHASEx
PHASEx
PHASEx
PHASEx
DRP
2
3
2
3
BST
are chosen according to Equations (15) and (16), and the selection of compensation types
V
(
F B
VDAC
RA
V
BIAS
RA
(
V
HOTSET
PHASEx
HOTSET
PHASEx
RCP
1 (
V
V
PHASEx1
-
+
Figure 18. Voltage loop compensation network
BIAS
BIAS
PHASEx1
RA
R
CCP1
V
PHASEx
BIAS
EAOUT
V
PHASEx
V
RA
1 (
BIAS
BIAS
V
CCP
HOTSET
1
PHASEx
and R
V
RA
)
,
HOTSET
R
PHASEx
V
PHASEx
HOTSET
PHASEx2
V
)
)
BIAS
EAOU T
R
1
PHASEx
)
R
and connect RMPIN+ or RMPIN- between R
1
PHASEx
VO+
VDRP
1
(b) Type III compensation
RFB1
RFB
RDRP
CFB
FB
VDAC
RCP
(23)
(24)
(25)
(26)
-
+
IR3082PbF
CCP1
EAOUT
01/31/05
CCP
PHASEx2
EAOUT
PHASEx
and
,