ISL6336BIRZ Intersil, ISL6336BIRZ Datasheet - Page 23

• Manufacturer Part Number: ISL6336BIRZ
• Description: IC CTRLR PWM SYNC BUCK 48-QFN
• Manufacturer: Intersil

Specifications of ISL6336BIRZ

• Applications: Controller, Intel VR11.1
• Voltage - Input: 3 ~ 12 V
• Number Of Outputs: 1
• Voltage - Output: 0.5 ~ 1.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-VQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Based on the NTC temperature characteristics and the
desired threshold of VR_HOT signal, the pull-up resistor
R
R
temperature t3.
R
TM1
NTC(t3)
FIGURE 14. BLOCK DIAGRAM OF THERMAL MONITORING
FIGURE 16. VR_HOT SIGNAL vs TM VOLTAGE
o
TM1
FIGURE 15. THE RATIO OF TM VOLTAGE TO NTC
0.333*V
C
0.391*V
VR_FAN
VR_HOT
TM
of TM pin is given by Equation 20:
=
VCC
R
R
100
TM
TM1
CC
90
80
70
60
50
40
30
20
2.75xR
NTC
CC
is the NTC resistance at the VR_HOT threshold
0
FUNCTION
TEMPERATURE WITH RECOMMENDED PARTS
NTC t3
20
(
0.333V
)
40
TEMPERATURE (°C)
CC
60
23
t2
80
t3
100
TEMPERATURE
VR_HOT
120
140
(EQ. 20)
ISL6336B
The NTC resistance at the set point T2 signal can be
calculated as:
With the NTC resistance value obtained from Equations 21
and 22, the temperature value t2 and t1 can be found from
the NTC datasheet.
Temperature Compensation
ISL6336B supports inductor DCR sensing, or resistive
sensing techniques. The inductor DCR has a positive
temperature coefficient of about +0.385%/°C. Because the
voltage across inductor is sensed for output current
information, the sensed current has the same positive
temperature coefficient as the inductor DCR.
In order to obtain the correct current information, there
should be a way to correct the temperature impact on the
current sense component. The ISL6336B provides two
methods: integrated temperature compensation and external
temperature compensation.
Integrated Temperature Compensation
When the TCOMP voltage is equal to or greater than V
ISL6336B will utilize the voltage at the TM and TCOMP pins to
compensate the temperature impact on the sensed current.
The block diagram of this function is shown in Figure 17.
When the TM NTC is placed close to the current sense
component (inductor), the temperature of the NTC will track
the temperature of the current sense component. Therefore,
the TM voltage can be utilized to obtain temperature of the
current sense component.
R
R
o
c
NTC t2
NTC t1
FIGURE 17. BLOCK DIAGRAM OF INTEGRATED
V
V
CC
CC
(
(
R
R
R
R
TCOMP
NTC
TC2
TM1
TC1
)
)
TM
=
=
1.267xR
1.644xR
TEMPERATURE COMPENSATION
NON-LINEAR
4-BIT
NTC t3
NTC t3
D/A
A/D
A/D
(
(
)
)
k
i
I
6
DROOP IOUT AND
OVERCURRENT
PROTECTION
I
5
CHANNEL
CURRENT
SENSE
I
4
I
3
August 31, 2010
I
2
(EQ. 21)
(EQ. 22)
CC
I
FN6696.2
1
/15,
I
I
I
I
I
I
Sen6
Sen5
Sen4
Sen3
Sen2
Sen1