ISL62881 Datasheet, PDF (2/35 Pages) Intersil Corporation – Single-Phase PWM Regulator for IMVP-6.5™ Mobile CPUs and GPUs

Pin Configurations
ISL62881
(28 LD TQFN)
TOP VIEW
ISL62881, ISL62881B
ISL62881B
(32 LD TQFN)
TOP VIEW
28 27 26 25 24 23 22
CLK_EN# 1
PGOOD 2
RBIAS 3
VW 4
COMP 5
FB 6
VSEN 7
GND PAD
(BOTTOM)
21 VID1
20 VID0
19 VCCP
18 LGATE
17 VSSP
16 PHASE
15 UGATE
8 9 10 11 12 13 14
32 31 30 29 28 27 26 25
PGOOD 1
RBIAS ₂
VR_TT# 3
NTC 4
GND 5
VW 6
COMP 7
FB 8
GND PAD
(BOTTOM)
24 VID1
23 VID0
22 VCCP
21 LGATEb
20 LGATEa
19 VSSP
18 PHASE
17 UGATE
9 10 11 12 13 14 15 16
Pin Function Description
GND (Bottom Pad)
Signal common of the IC. Unless otherwise stated,
signals are referenced to the GND pin.
CLK_EN#
Open drain output to enable system PLL clock; goes
active 13 switching cycles after V_core is within 10% of
V_boot.
PGOOD
Power-Good open-drain output indicating when the
regulator is able to supply regulated voltage. Pull-up
externally with a 680Ω resistor to VCCP or 1.9kΩ to 3.3V.
RBIAS
A resistor to GND sets internal current reference. A
147kΩ resistor sets the controller for CPU core
application and a 47kΩ resistor sets the controller for
GPU core application.
VR_TT#
Thermal overload output indicator.
NTC
Thermistor input to VR_TT# circuit.
VW
A resistor from this pin to COMP programs the switching
frequency (8kΩ gives approximately 300kHz).
COMP
This pin is the output of the error amplifier. Also, a
resistor across this pin and GND adjusts the overcurrent
threshold.
FB
This pin is the inverting input of the error amplifier.
VSEN
Remote core voltage sense input. Connect to
microprocessor die.
RTN
Remote voltage sensing return. Connect to ground at
microprocessor die.
ISUM- and ISUM+
Droop current sense input.
VDD
5V bias power.
VIN
Battery supply voltage, used for feed-forward.
IMON
An analog output. IMON outputs a current proportional to
the regulator output current.
BOOT
Connect an MLCC capacitor across the BOOT and the
PHASE pins. The boot capacitor is charged through an
internal boot diode connected from the VCCP pin to the
BOOT pin, each time the PHASE pin drops below VCCP
2
FN6924.0
October 26, 2009