ir3092 International Rectifier Corp., ir3092 Datasheet - Page 25

• Manufacturer Part Number: ir3092
• Description: 2 Phase Opteron, Athlon, Or Vr10.x Control Ic
• Manufacturer: International Rectifier Corp.

R
and transient load response. Choose the desired crossover frequency fc1 around fc estimated by Equation (13) and
determine R
C
ceramic capacitor between 10pF and 220pF is usually enough. In equation (14), V
comparator gain (refer to equation (22)).
Type III Compensation
Determine the compensation at no load, the worst case condition. Assume the time constant of the resistor and capacitor
across the output inductors matches that of the inductor, the crossover frequency of the voltage loop can be estimated by
Equations (16).
Choose the desired crossover frequency fc1 around fc estimated by Equation (16). Select other components to ensure the
slope of close loop gain is -20dB/Dec around the crossover frequency. Choose resistor R
and determine C
R
and transient load response. Determine R
comparator gain defined by Equation (22).
COMP
CP1
COMP
is optional and may be needed in some applications to reduce the jitter caused by the high frequency noise. A
and C
and C
Page 25 of 37
COMP and
COMP
COMP
FB
C
C
R
FB
DRP
FB
and C
have limited effect on the crossover frequency, and are used only to fine tune the crossover frequency
f
have limited effect on the crossover frequency, and are used only to fine tune the crossover frequency
C
1
C
COMP.
4
1
2
2S
(
DRP
S
R
C
R
R
FB
COMP
*
COMP
FB
from Equations (18) and (19).
f
C
C

1
E
1
R
R
R
to
DRP
FB
R
COMP
G
10
2 ( S
R
C
1
FB
CS
)
DRP
COMP
1
*
R
R
C
R
COMP
FB
L
f
FB
2 ( S
C
FB
E
1
COMP
1
V
)
10
2
IN
C
2
3
R
E
f
LE
R
R
L
and C
C
F
E
FB
1
COMP
L
)
M
V
E
2
I
C
COMP
C
E
L
F
E
E
M
R
C
FB
from Equations (20) and (21), where F
E
(18)
(19)
(17)
(16)
R
FB
IN
is the input voltage, F
FB1
(14)
(15)
(21)
according to Equation (17),
(20)
06/25/04
M
IR3092
M
is the PWM
is the PWM