ISL9502
®
Data Sheet
July 17, 2006
FN9275.1
Two-Phase PWM Controller for Graphics
Processor Units (GPU)
Features
• Precision Two-phase Buck PWM controller
- 0.5% System Accuracy Over Temperature
- Active Voltage Positioning Capability
Increase in GPU clock frequency is accompanied by
associated increase in the demand for power and transient-
current slew rate. At the same time, the voltage tolerance
requirement during steady-state and transient operation is
becoming more stringent of advanced GPU. The ISL9502 is
a two-phase PWM controller with embedded gate drivers,
which is tailored to meet the power and dynamic
• Internal Gate Driver with 2A Driving Capability
• Superior Load Transient Response
• Dynamic Phase Adding/Dropping
• Voltage Selection Input
requirements. The two-phase buck converter uses two
interleaved channels to effectively double the output voltage
ripple frequency and thereby reduce output voltage ripple
amplitude with fewer components, lower component cost,
reduced power dissipation, and smaller real estate area.
- 6-Bit VSEL Input
- 0.500V to 1.500V in 25mV Steps
- Supports VSEL Change On-The-Fly
• Multiple Current-Sensing Schemes Supported
- Lossless Inductor DCR Current Sensing
- Precision Resistive Current Sensing
The heart of the ISL9502 is the patented R3 (Robust Ripple
Regulator®) modulator. Compared with the traditional multi-
phase buck regulator, R3 technology has the fastest transient
response. This is due to the R3 modulator commanding
variable switching frequency during a load transient.
• Thermal Monitor
• User Programmable Switching Frequency
• Differential Remote GPU Voltage Sensing
• Static and Dynamic Current Sharing
At heavy load operation of the active mode, ISL9502
commands the two phase continuous conduction mode
(CCM) operation. While the pin SET3 is asserted at the
medium or light load, the ISL9502 smoothly disables one
phase and operates in a one-phase operation. Once in one-
phase operation, when the GPU further lowers the load
current, the ISL9502 enables diode emulation to maximize
efficiency at light load depending on the logic of SET1 and
SET2.
• Overvoltage, Undervoltage, and Overcurrent Protection
• Pb-Free Plus Anneal Available (RoHS Compliant)
Ordering Information
PART
PART
TEMP.
(°C)
PKG.
NUMBER
MARKING
PACKAGE DWG. #
A 6-bit digital-to-analog converter (DAC) allows dynamic
adjustment of the output voltage from 0.500V to 1.500V with
25mV step. A 0.5% system accuracy of the core output
voltage over temperature is achieved by the ISL9502.
ISL9502CRZ ISL9502CRZ -10 to 100 48 Ld7x7 QFN L48.7x7
(Note) (Pb-free)
ISL9502CRZ-T ISL9502CRZ -10 to 100 48 Ld7x7 QFN L48.7x7
(Note) (Pb-free)
A unity-gain differential amplifier is provided for remote GPU
die sensing. This allows the voltage on the GPU die to be
accurately measured and regulated. Current sensing can be
realized using either lossless inductor DCR sensing or
precision resistor sensing. A single NTC thermistor network
can thermally compensates the gain and the time constant of
the DCR variations. Droop control, also referred as adaptive
voltage positioning (AVP), is implemented in ISL9502 to
reduce output decoupling capacitors and achieve more cost-
effective transient-load regulation.
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which are RoHS compliant and
compatible with both SnPb and Pb-free soldering operations. Intersil
Pb-free products are MSL classified at Pb-free peak reflow
temperatures that meet or exceed the Pb-free requirements of
IPC/JEDEC J STD-020.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Copyright Intersil Americas Inc. 2006. All Rights Reserved. R Technology™ is a trademark of Intersil Americas Inc.
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