isl62883c Intersil Corporation, isl62883c Datasheet - Page 3

• Manufacturer Part Number: isl62883c
• Description: Multiphase Pwm Regulator For Imvp-6.5? Mobile Cpus And Gpus
• Manufacturer: Intersil Corporation

Functional Pin Descriptions
ISL62883C
14, 15
10
11
12
13
16
17
18
19
20
21
22
23
24
1
2
3
4
5
6
7
8
9
-
INSE3/FB2
ISUM- and
SYMBOL
VR_TT#
UGATE1
PHASE1
PGOOD
LGATE1
ISUM+
BOOT1
VSSP1
RBIAS
ISEN2
ISEN1
PWM3
COMP
VSEN
IMON
PSI#
GND
VDD
NTC
RTN
VIN
VW
FB
3
Signal common of the IC. Unless otherwise stated, signals are referenced to the GND pin.
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.
Low load current indicator input. When asserted low, indicates a reduced load-current condition.
A resistor to GND sets internal current reference. Use 147kΩ or 47kΩ. The choice of Rbias value,
together with the ISEN2 pin configuration and the external resistance from the COMP pin to
GND, programs the controller to enable/disable the overshoot reduction function and to select
the CPU/GPU mode.
Thermal overload output indicator.
Thermistor input to VR_TT# circuit.
A resistor from this pin to COMP programs the switching frequency (8kΩ gives approximately
300kHz).
This pin is the output of the error amplifier. Also, a resistor across this pin and GND adjusts the
overcurrent threshold.
This pin is the inverting input of the error amplifier.
When the ISL62883C is configured in 3-phase mode, this pin is ISEN3. ISEN3 is the individual
current sensing for phase 3. When the ISL62883C is configured in 2-phase mode, this pin is
FB2. There is a switch between the FB2 pin and the FB pin. The switch is on in 2-phase mode
and is off in 1-phase mode. The components connecting to FB2 are used to adjust the
compensation in 1-phase mode to achieve optimum performance.
Individual current sensing for Phase 2. When ISEN2 is pulled to 5V VDD, the controller will
disable Phase 2.
Individual current sensing for phase 1.
Remote core voltage sense input. Connect to microprocessor die.
Remote voltage sensing return. Connect to ground at microprocessor die.
Droop current sense input.
5V bias power.
Battery supply voltage, used for feed-forward.
An analog output. IMON outputs a current proportional to the regulator output current.
Connect an MLCC capacitor across the BOOT1 and the PHASE1 pins. The boot capacitor is
charged through an internal boot diode connected from the VCCP pin to the BOOT1 pin, each
time the PHASE1 pin drops below VCCP minus the voltage dropped across the internal boot
diode.
Output of the Phase-1 high-side MOSFET gate driver. Connect the UGATE1 pin to the gate of the
Phase-1 high-side MOSFET.
Current return path for the Phase-1 high-side MOSFET gate driver. Connect the PHASE1 pin to
the node consisting of the high-side MOSFET source, the low-side MOSFET drain, and the output
inductor of Phase-1.
Current return path for the Phase-1 low-side MOSFET gate driver. Connect the VSSP1 pin to the
source of the Phase-1 low-side MOSFET through a low impedance path, preferably in parallel
with the traces connecting the LGATE1a and the LGATE1b pins to the gates of the Phase-1 low-
side MOSFETs.
Output of the Phase-1 low-side MOSFET gate driver. Connect the LGATE1 pin to the gate of the
Phase-1 low-side MOSFET.
PWM output for Phase 3. When PWM3 is pulled to 5V VDD, the controller will disable Phase-3
and allow other phases to operate.
ISL62883C
DESCRIPTION
March 18, 2010
FN7557.1