ir3092 International Rectifier Corp., ir3092 Datasheet - Page 27

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

External Components of IR3092
Oscillator Resistor Rosc
Soft Start Capacitor C
DESIGN EXAMPLE
IR3092 Demo Board Rev.2 for VRD10.0 FMB1.5
Input Voltage: V
DAC Voltage: V
No Load Output Voltage Offset: V
Output Current: I
Output Current Limit set point: I
Output Impedance: R
VCC Ready to VCC Power Good Delay: t
Soft Start Time: t
Dynamic VID Down-Slope Slew Rate: SR
Power Stage Design
Control IC: IR3092
Phase Number: n=2
Switching Frequency: f
Output Inductor(per phase): L=0.45 uH, R
Output Capacitors: C
Once the switching frequency is chosen, R
IR3092 data sheet. For switching frequency of 180 kHz per phase,
Choose R
Calculate the soft start capacitor from the required soft start time 6mS.
With the selected Css value, we can calculate the following delay times:
The Over-Current fault latch delay time
Page 27 of 37
Specifications:
C
t
OCDEL
SS
I
CHG
C
OSC
V
I
SS
DISCHG
O
*
=47.5k
*
t
SS
DAC
I
'
=12 V
O
SS
V
=80 A DC
=2 mS
=1.35 V
55
E
O
=0.011F, R
SS
. 1
=1.3 m
SW
0
*
35
1 .
10
50
=180 kHz
*

10
5 .
§
6
25
*
*
¨
LIMIT
6
10
2
*
*
CE
O_NLOFST
10
*
¨
. 0
10
6
=100 A
=1 m
§
25
3
§
3
t
OCDEL
VccPG
DOWN
L
0
=0.7 m
=25 mV
8
5 .
OSC
3 .
mS
=0-10mS
will be:
*
=2.5mV/uS
10
can be determined from the curve in the datasheet of
§
(1m
8
F
when winding temperatures around 120C)
Choose C
SS =
0.1 uF
06/25/04
IR3092