ir3084u International Rectifier Corp., ir3084u Datasheet - Page 37

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

Using the calculated value of C
voltage of 1.300V during startup with Boot Mode using Equation 4a;
No Load Output Voltage Setting Resistor RVSETPT, R
First, use Equations (19) and (20) to calculate the current sense resistors R
design, in the next section, R
Second, calculate the total input offset voltage (V
From the IR3086A data sheet, typical values for the I
and 0.40µA, respectively.
Next, derive the intermediate calculations (A,B,C,D) as shown below before finally calculating R
using Equations (7) and (8). From Figure 15 on page Error! Bookmark not defined., the I
determined to be 40µA at R
Choose the closest standard resistor value to this with 1% tolerance or RVESTPT = 124ohms.
Page 37 of 47
V
VSETPT
TD
C
B
D
RVSETPT
A
CS_TOFST
=
=
=
=
=
4
. 0
V
V
V
Io
=
O
CS_TOFST
3984
O
*
_
I
_
C
NLOFST
SOURCE
NLOFST
R
=
=
=
VDAC
L
n
V
=
. 0
*
(
CS_OFST
*G
A
G
A
VSETPT
55
+
+
−
CSA
I
*
∗
CSA
VSETPT
mV
Io
V
(
D
B
VDAC
OSC
OS
+
+
−
*
CS+
−
+
V
+
V
_
Ro
C
C
VDAC
(
=30.1kΩ and a typical value for the offset voltage of the error amplifier is 0.0mV.
CS
EA
(
OS_EA
is determined to be 10KΩ and R
I
. 0
*
−
=
CSIN
_
−
=
−
25
B
, find the positive VID voltage rise time (TD4) to the specified nominal DAC
TOFST
D
. 0
40
V
15
1
+
)
=
OS
1 .
*
00494
x
∗
=
*
10
V
0.574*10
10
_
*
10
R
EA
)
. 0
. 0
−
G
CS
−
=
6
−
3984
6
CSA
=
3984
3
+
*
33
90
=
) (
10
15
−
−
+
123
nF
0
uA
K
CS_TOFST
*
V
0 .
+
*
−
I
10
Ω
OS
3
CSIN
mV
. 0
. 0
*34
5 .
*
CSIN+
) (
−
_
(
015
1710
ohms
−
. 1
3
EA
−
+
300
=
+
) of the current sense amplifiers using Equation (6).
∗
. 0
and I
=
FB
130
−
0.0mV
. 0
R
40
130
−
V
CS
. 0
015
and Adaptive Voltage Positioning Resistor R
. 0
*
*
−
0195
CSIN−
−
10
)
. 1
0195
*
1
CS−
20
1 .
. 0
−
=
6
V
bias currents are determined to be 0.25µA
60
*
is found to be 6.19KΩ.
*
*
0.0.0195
)
−
. 0
10
7
. 6
*
=
. 0
1710
19
10
73
−
015
3
K
−
CS+
−
3 .
3
Ω
*
0
us
=
and R
0 .
)
34
=
. 0
mV
. 0
+
00494
574
. 0
CS−
=
574
. 0
, respectively. For this
mV
V
1710
VSETPT
*
10
IR3084U
VSETPT
−
3
bias current is
*
34
9/14/2005
and RDRP
+
0
0 .
mV
DRP