IR3502MTRPBF International Rectifier, IR3502MTRPBF Datasheet - Page 29

• Manufacturer Part Number: IR3502MTRPBF
• Description: IC XPHASE3 CONTROLLER 32-MLPQ
• Manufacturer: International Rectifier
• Series: XPhase3™r

Specifications of IR3502MTRPBF

• Applications: Processor
• Current - Supply: 8mA
• Voltage - Supply: 8 V ~ 16 V
• Operating Temperature: 0°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 32-MLPQ
• Package: 32-Lead MLPQ
• Circuit: X-Phase Control IC
• Switch Freq (khz): 250kHz to 1.5MHz
• Pbf: PbF Option Available
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: IR3502MTRPBFTR

Thermistor R
The threshold voltage of VRHOT comparator is fixed at 1.6V, and a negative temperature coefficient (NTC)
thermistor R
thermistor resistance at allowed maximum temperature T
Select the series resistor R
operational temperature range. Then calculate R
TMAX from (28).
VCCL Capacitor C
driven. The linear regulator supplies the bias and gate drive current of the phase ICs. A 4.7uF normally ensures
stable VCCL performance for Intel VR11 applications.
VCCL Regulator Drive Resistor R
minimum input voltage requirements. The following equation gives an estimate of the average load current of
the switching phase ICs.
Q
VCCL, the maximum R
Due to limited pull down capability of the VCCLDRV pin, make sure the following condition is satisfied.
In the above equation, V
above condition is not satisfied there is a need to use a device with higher β
be used instead of a single NPN transistor.
Current Monitor Filter
A filter is added to isolate the CPU from rapid changes in the load current and trigger false response. A filter with
300 us time constant provides adequate delay for Intel VR11.1 response. A 1k resistor between IMON and local
ground helps equalize the source and sink current of the IMON pin.
The capacitor is selected based on the stability requirement of the linear regulator and the load current to be
The drive resistor is primarily dependent on the load current requirement of the linear regulator and the
gb
and Q
Page 29 of 39
gt
THERM
are the gate charge of the top and bottom FET. For a minimum input voltage and a maximum
THERM
VCCL
is required to sense the temperature of the power stage. If we pre-select R
and Over Temperature Setting Resistors R
VCCLDRV
I
( min) and V
HOTSET2
required to use the full pull-down current of the VCCL driver is given by
I
drive
VCCLDRV
V
to linearize the NTC thermistor, which has non-linear characteristics in the
R
R
R
I
_
(max)
I
TMAX
VCCLDRV
( max) is the minimum and maximum anticipated input voltage. If the
HOTSET
avg
R
=
=
VCCLDRV
1
−
[
R
(
=
THERM
Q
0
=
7 .
(
gb
V
R
HOTSET1
−
I
TMAX
+
(min)
6
*
I
Q
drive
8 .
EXP
V
gt
MAX
+
)
_
[
−
<
R
avg
B
⋅
corresponding to the allowed maximum temperature
THERM
HOTSET
0
10
f
is calculated from (27).
sw
7 .
/
mA
β
−
+
1
min
HOTSET1
6 .
6
( *
2
10
)
8 .
T
( *
mA
V
L
_
VCCL
1
MAX
]
⋅
and R
n
min
−
or Darlington configuration can
T
−
_
. 1
HOTSET2
ROOM
1
) 6
)]
July 28, 2009
THERM
IR3502
, the NTC
(29)
(30)
(31)
(27)
(28)