IR3502MPBF International Rectifier, IR3502MPBF Datasheet - Page 27

• Manufacturer Part Number: IR3502MPBF
• Description: Complete VR11.0 or VR11.1 power solution.
• Manufacturer: International Rectifier

Specifications of IR3502MPBF

• Package: 32-Lead MLPQ
• Circuit: X-Phase Control IC
• Switch Freq (khz): 250kHz to 1.5MHz
• Pbf: PbF Option Available

The soft start delay time (TD1) and VR ready delay time (TD3) are determined by (8) to (9) respectively.
Once C
VDAC Slew Rate Programming Capacitor C
The slew rate of VDAC slope SR
where I
The resistor R
Current Report Gain and Thermal Compensation
Intel VR11.1 specifications require IMON to report the core maximum load current of the CPU be reported as 1 V
nominal. The core maximum current can be different for different platforms. The IMON tuning resistors can
therefore be adjusted and thermally compensated to adjust the load current gain with respect to the IMON. The
expressions that govern the relationship between load current, IMON, and VDRP at room temperature are given
by
The change in inductor DCR with temperature is compensated by an equivalent variation in the RTHERM. The
following equations derive the RTCMP1 and RTCMP2 if RTCMP3 and the thermistor (RTHERM and β
fixed.
SINK
SS/DEL
Page 27 of 39
is the sink current of VDAC pin. The slew rate of VDAC up-slope is the same as that of down-slope.
VDAC
is chosen, the minimum over-current fault latch delay time
K
IMON
is used to compensate VDAC circuit and can be calculated as follows
THERM
VDRP
_
=
room
=
50
VDAC
t
mV
OCDEL
TD
C
=
R
SS
L
1 (
3
+
/
DOWN
_
DEL
=
MAX
−
+
1
3
I
=
C
1
50
3
o
⋅
C
R




max
=
TD
SS
⋅
C
VDAC
VDAC




mV
R
=
TD
/
can be programmed by the external capacitor C
SS
R
L
1
DEL
R
L
_
I
=
/
room
2
_
)
DEL
I
DISCHG
L
=
V
=
room
*
C
CHG
n
*
,
_
O
n
SR
I
SS
4 (
VDAC
room
K
2
⋅
CHG
*
I
G
⋅
0 .
/
I
⋅
SINK
c
DOWN
G
DEL
. 0
CHG
π
cs
_
−
cs
∗
room
12
=
V

⋅  

⋅
and Resistor R
1 [

⋅  

1 *
900
O
TD






1
)
+
=
=
4 .
=
1
+
=
2
+
3850
44
SR
kHz
(
C
1
=
*
(
R
C
(
RTCMP
52
SS
*
C
RTCMP
DOWN
V
SS
L
55
10
52
SS
O
_
/
5 .
⋅
/
DEL
room
52
DEL
C
5 .
*
/
−
*
*
DEL
6
n
10
10
VDAC
10
*
5 .
10
*
⋅
*
) 2
*
−
) 2
G
1 *
−
−
. 0
6
4 (
10
−
6
6
VDAC
II
6
cs
II
4 .
0 .
12
∗
−
(
)
(
6
RTCMP
(
−
RTCMP
T
,
V
t
L
K
OCDEL
O
RTCMP
RTCMP
_
)
c
MAX
_
t
max
1
1
+
+
−
is fixed and can be quantified as
RTHERM
3
RTHERM
3
=
T
room
(
R
L
)]
_
max
VDAC
n
_
_
July 28, 2009
⋅
room
G
room
as defined in (11),
cs
)
IR3502
)
)

⋅ 


⋅ 

I
I
o
o
THERM
) are
(13)
(14)
(15)
(16)
(10)
(11)
(12)
(7)
(8)
(9)