ir3084u International Rectifier Corp., ir3084u Datasheet - Page 40

• Manufacturer Part Number: ir3084u
• Description: Xphasetm Vr10, Vr11 & Opteron/athlon64 Control Ic
• Manufacturer: International Rectifier Corp.

IR3086 PHASE IC COMPONENTS
PWM Ramp Resistor R
Set the PWM ramp magnitude V
calculate the resistor R
Inductor Current Sensing Capacitor C
Choose C
The bias currents of CSIN+ and CSIN− are 0.25uA and 0.4uA respectively. Calculate resistor R
Equation (20);
Over Temperature Setting Resistors R
Use central over temperature setting and set the temperature threshold at 115 ºC, which corresponds the IC die
temperature of 116 ºC. Calculate the HOTSET threshold voltage corresponding to the temperature thresholds
using Equations (21) and (22);
Page 40 of 47
V
R
R
R
R
CS+
HOTSET
PWMRMP
CS
HOTSET
CS
−
+
=47nF and calculate R
=
=
2
. 0
L
=
0
C
=
=
Choose a standard resistor value, R
25
4 .
=
. 4
CS
R
V
R
12
73
+
∗
L
V
IN
HOTSET
PWMRMP
R
BIAS
*
=
RAMP
∗
∗
CS
10
400*10
220
f
+
−
SW
1
−
=
3
V
∗
and Capacitor C
*
*
∗
V
HOTSET
. 0
using Equation (18);
T
0
10
C
HOTSET
25
4 .
J
PWMRMP
47
PWMRMP
−
3
+
9
CS+
∗
. 1
∗
/(0.47
*
10
10
220*10
241
=
CS+
using Equation (19);
0 .
HOTSET1
−
∗
20
9
*
to 0.8V. Choose 220pF for the PWM ramp capacitor C
=
[ln(V
*
10
and Resistors R
6
*
10
. 4
8 .
10
3
RAMP
73
−
−
−
=
12
3
3
and R
IN
. 1
)
*
6
∗
∗
10
=
79
2 .
−
. 1
[ln(12
V
PWMRMP
10.0kΩ
V
k
−
79
1.30
3
Ω
O
DAC
HOTSET2
∗
,
=
116
)
. 7
−
−
CS+
14
=15.8kΩ.
+
ln(V
1.30)
. 1
choose R
k
and R
Ω
241
IN
−
−
=
V
ln(12
CS−
. 1
DAC
CS−
79
V
−
= 6.19kΩ
−
, choose R
V
1.30
PWMRMP
−
0.8)]
)]
HOTSET1
IR3084U
=
15.8k Ω
=20.0kΩ,
9/14/2005
PWMRMP
CS−
,
using
and