June 30, 2009
PWM DC/DC Controller with VID Inputs for
Portable GPU Core-Voltage Regulator
The ISL62873 is a Single-Phase Synchronous-Buck PWM
voltage regulator featuring Intersil’s Robust Ripple Regulator
(R3) Technology™. The wide 3.3V to 25V input voltage range
is ideal for systems that run on battery or AC-adapter power
sources. The ISL62873 is a low-cost solution for applications
requiring dynamically selected slew-rate controlled output
voltages. The soft-start and dynamic setpoint slew-rates are
capacitor programmed. Voltage identification logic-inputs
select two resistor-programmed setpoint reference voltages
that directly set the output voltage of the converter between
0.5V to 1.5V, and up to 3.3V using a feedback voltage divider.
Optionally, an external reference such as the DAC output from
a microcontroller, can be used by either IC to program the
setpoint reference voltage, and still maintain the controlled
slew-rate features. Robust integrated MOSFET drivers and
Schottky bootstrap diode reduce the implementation area and
lower component cost.
Intersil’s R3 Technology™ combines the best features of
both fixed-frequency and hysteretic PWM control. The PWM
frequency is 300kHz during static operation, becoming
variable during changes in load, setpoint voltage, and input
voltage when changing between battery and AC-adapter
power. The modulators ability to change the PWM switching
frequency during these events in conjunction with external
loop compensation produces superior transient response.
For maximum efficiency, the converter automatically enters
diode-emulation mode (DEM) during light-load conditions
such as system standby.
(16 LD 2.6X1.8 µTQFN)
• Input Voltage Range: 3.3V to 25V
• Output Voltage Range: 0.5V to 3.3V
• Output Load up to 30A
• Flexible Output Voltage Programmability
- 1-Bit VID Selects Two Independent Setpoint Voltages
- Simple Resistor Programming of Setpoint Voltages
- Accepts External Setpoint Reference such as DAC
• ±0.75% System Accuracy: -10°C to +100°C
• One Capacitor Programs Soft-start and Setpoint Slew-rate
• Fixed 300kHz PWM Frequency in Continuous Conduction
• External Compensation Affords Optimum Control Loop
• Automatic Diode Emulation Mode for Highest Efficiency
• Integrated High-current MOSFET Drivers and Schottky
Boot-Strap Diode for Optimal Efficiency
• Choice of Overcurrent Detection Schemes
- Lossless Inductor DCR Current Sensing
- Precision Resistive Current Sensing
• Power-Good Monitor for Soft-Start and Fault Detection
• Fault Protection
- Overcurrent (DCR-Sense or Resistive-Sense Capability)
- Over-Temperature Protection
- Fault Identification by PGOOD Pull-Down Resistance
• Pb-Free (RoHS compliant)
• Mobile PC Graphical Processing Unit VCC Rail
• Mobile PC I/O Controller Hub (ICH) VCC Rail
• Mobile PC Memory Controller Hub (GMCH) VCC Rail
• Built-In Voltage Margin for System-Level Test
ISL62873HRUZ-T* -10 to +100 16 Ld 2.6x1.8 µTQFN L16.2.6x1.8A
Tape and Reel
*Please refer to TB347 for details on reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets; molding compounds/die attach
materials and NiPdAu plate - e4 termination finish, which is 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.
1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2009. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.