ISL6316IRZ-T Intersil, ISL6316IRZ-T Datasheet - Page 21

• Manufacturer Part Number: ISL6316IRZ-T
• Description: IC CTRLR PWM 4PHASE ENH 40-QFN
• Manufacturer: Intersil

Specifications of ISL6316IRZ-T

• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Frequency - Max: 275kHz
• Duty Cycle: 66.7%
• Voltage - Supply: 4.75 V ~ 5.25 V
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-VFQFN, 40-VFQFPN
• Frequency-max: 275kHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

FIGURE 14. BLOCK DIAGRAM OF THERMAL MONITORING
FIGURE 15. THE RATIO OF TM VOLTAGE TO NTC
FIGURE 16. VR_HOT AND VR_FAN SIGNAL vs TM VOLTAGE
o
c
VR_HOT
VR_FAN
0.39*VCC
0.33*VCC
0.28*VCC
TM
100
VCC
R
R
90
80
70
60
50
40
30
20
TM
TM1
NTC
0
FUNCTION
TEMPERATURE WITH RECOMMENDED PARTS
20
V
0.33V
0.28V
TM
40
/V
TEMPERATURE (°)
CC
CC
CC
vs TEMPERATURE
60
21
T1
80
T2
T3
100
TEMPERATURE
120
VR_FAN
VR_HOT
140
ISL6316
The NTC resistance at the set point T2 and release point T1
of VR_FAN signal can be calculated as:
With the NTC resistance value obtained from Equations17
and 18, the temperature value T2 and T1 can be found from
the NTC datasheet.
Temperature Compensation
ISL6316 supports inductor DCR sensing, MOSFET r
sensing, or resistive sensing techniques. Both inductor DCR
and MSOFET r
coefficient, which is about +0.38%/°C. Because the voltage
across inductor or MOSFET is sensed for the output current
information, the sensed current has the same positive
temperature coefficient as the inductor DCR or MOSFET
r
In order to obtain the correct current information, there should
be a way to correct the temperature impact on the current
sense component. ISL6316 provides two methods: integrated
temperature compensation and external temperature
compensation.
Integrated Temperature Compensation
When TCOMP voltage is equal or greater than VCC/15,
ISL6316 will utilize the voltage at TM and TCOMP pins to
compensate the temperature impact on the sensed current.
The block diagram of this function is shown in Figure 17.
R
R
° C
DS(ON)
FIGURE 17. BLOCK DIAGRAM OF INTEGRATED
NTC T2
NTC T1
V
V
CC
CC
R NTC
R TC2
(
(
R TM1
R TC1
TCOMP
.
)
)
TM
=
=
1.267xR
1.644xR
TEMPERATURE COMPENSATION
DS(ON)
NON-LINEAR
4-BIT
D/A
A/D
A/D
NTC T3
NTC T3
have the positive temperature
(
(
K I
)
)
DROOP AND OVERCURRENT
CHANNEL CURRENT
I 4
PROTECTION
SENSE
I 3
I 2
December 12, 2006
I 1
DS(ON)
(EQ. 17)
(EQ. 18)
FN9227.1
I
I
I
I
SEN4
SEN3
SEN2
SEN1