ISL6327IRZ-T Intersil, ISL6327IRZ-T Datasheet - Page 9

• Manufacturer Part Number: ISL6327IRZ-T
• Description: IC CTRLR PWM 6PHASE BUCK 48-QFN
• Manufacturer: Intersil

Specifications of ISL6327IRZ-T

• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Frequency - Max: 275kHz
• Duty Cycle: 25%
• 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: 48-VQFN
• Frequency-max: 275kHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

FB and COMP - The inverting input and the output of the
error amplifier respectively. FB can be connected to VDIFF
through a resistor. A properly chosen resistor between
VDIFF and FB can set the load line (droop), when IDROOP
pin is tied to FB pin. The droop scale factor is set by the ratio
of the ISEN resistors and the inductor DCR or the dedicated
current sense resistor. COMP is tied back to FB through an
external R-C network to compensate the regulator.
DAC and REF - The DAC pin is the output of the precision
internal DAC reference. The REF pin is the positive input of
the Error Amp. In typical applications, a 1kΩ, 1% resistor is
used between DAC and REF to generate a precision offset
voltage. This voltage is proportional to the offset current
determined by the offset resistor from OFS to ground or
VCC. A capacitor is used between REF and ground to
smooth the voltage transition during Dynamic VID™
operations.
PWM1, PWM2, PWM3, PWM4, PWM5, PWM6 - Pulse
width modulation outputs. Connect these pins to the PWM
input pins of the Intersil driver IC. The number of active
channels is determined by the state of PWM3, PWM4,
PWM5, and PWM6. For 2-phase operation, connect PWM3
to VCC; similarly, PWM4 for 3-phase, PWM5 for 4-phase,
and PWM6 for 5-phase operation.
ISEN1+, ISEN1-; ISEN2+, ISEN2-; ISEN3+, ISEN3-;
ISEN4+, ISEN4-; ISEN5+, ISEN5-; ISEN6+, ISEN6- - The
ISEN+ and ISEN- pins are current sense inputs to individual
differential amplifiers. The sensed current is used for
channel current balancing, overcurrent protection, and droop
regulation. Inactive channels should have their respective
current sense inputs left open (for example, open ISEN6+
and ISEN6- for 5-phase operation).
For DCR sensing, connect each ISEN- pin to the node
between the RC sense elements. Tie the ISEN+ pin to the
other end of the sense capacitor through a resistor, R
The voltage across the sense capacitor is proportional to the
inductor current. Therefore, the sense current is proportional
to the inductor current, and scaled by the DCR of the
inductor and R
VR_RDY - VR_RDY indicates that the soft-start is completed
and the output voltage is within the regulated range around
VID setting. It is an open-drain logic output. When OCP or
OVP occurs, VR_RDY will be pulled to low. It will also be
pulled low if the output voltage is below the undervoltage
threshold.
CONFIGURATION
6-Phase
5-Phase
4-Phase
3-Phase
TABLE 1. PHASE FIRING SEQUENCE
ISEN
.
9
PHASE SEQUENCE
1 - 2 - 3 - 4 - 5 - 6
1 - 2 - 3 - 4 - 5
1 - 2 - 4 - 3
1 - 2 - 3
ISEN
.
ISL6327
OFS - The OFS pin provides a means to program a DC
offset current for generating a DC offset voltage at the REF
input. The offset current is generated via an external resistor
and precision internal voltage references. The polarity of the
offset is selected by connecting the resistor to GND or VCC.
For no offset, the OFS pin should be left unterminated.
TCOMP - Temperature compensation scaling input. The
voltage sensed on the TM pin is utilized as the temperature
input to adjust IDROOP and the overcurrent protection limit
to effectively compensate for the temperature coefficient of
the current sense element. To implement the integrated
temperature compensation, a resistor divider circuit is
needed with one resistor being connected from TCOMP to
VCC of the controller and another resistor being connected
from TCOMP to GND. Changing the ratio of the resistor
values will set the gain of the integrated thermal
compensation. When integrated temperature compensation
function is not used, connect TCOMP to GND.
OVP - The Overvoltage protection output indication pin. This
pin can be pulled to VCC and is latched when an overvoltage
condition is detected. When the OVP indication is not used,
keep this pin open.
IDROOP - IDROOP is the output pin of the sensed average
channel current, which is proportional to the load current. In
the application, which does not require loadline, leave this
pin open. In the application which requires load line, connect
this pin to FB so that the sensed average current will flow
through the resistor between FB and VDIFF to create a
voltage drop, which is proportional to the load current.
IOUT - IOUT has the same output as IDROOP with
additional OCP adjustment function. In actual application, a
resistor needs to be placed between IOUT and GND to
ensure the proper operation. The voltage at IOUT pin will be
proportional to the load current. If the voltage is higher than
2V, ISL6327 will go into the OCP mode, this means it will
shut down first and then hiccup. The additional OCP trip
level can be adjusted by changing the resistor value.
TM - TM is an input pin for VR temperature measurement.
Connect this pin through NTC thermistor to GND and a
resistor to VCC of the controller. The voltage at this pin is
reverse proportional to the VR temperature. ISL6327
monitors the VR temperature based on the voltage at the TM
pin and the output signals at VR_HOT and VR_FAN.
VR_HOT - VR_HOT is used as an indication of high VR
temperature. It is an open-drain logic output. It will be open
when the measured VR temperature reaches a certain level.
VR_FAN - VR_FAN is an output pin with open-drain logic
output. It will be open when the measured VR temperature
reaches a certain level.
May 5, 2008
FN9276.4