ISL6528
Dual Regulator-Standard Buck PWM and Linear Power Controller

Key Features

• Pb-Free Available (RoHS Compliant)
• Provides two regulated voltages
• One standard buck PWM
• One linear controller
• Small converter size
• 600kHz constant frequency operation
• Small external component count
• Excellent output voltage regulation
• Both outputs: ±2% over temperature
• Single 5V bias and bootstrap supply
• Output voltage range: 0.8V to 3.3V
• Simple single-loop voltage-mode PWM control design
• Fast PWM converter transient response
• High-bandwidth error amplifier
• Full 0-100% duty ratio
• Linear controller drives bipolar linear pass transistor
• Fully-adjustable outputs
• Undervoltage fault monitoring on both outputs

Description

The ISL6528 provides the power control and protection for two output voltages in high-performance graphics cards and other embedded processor applications. The dual-output controller drives an N-Channel MOSFET in a standard buck topology and a NPN pass transistor in a linear configuration. The ISL6528 provides both a regulated high current, low voltage supply and an independent, lower current supply integrated in an 8-lead SOIC package. The controller is ideal for graphics card applications where both graphics processing unit (GPU) and memory supplies are required.

The standard buck converter is a simple, single feedback loop, voltage-mode control with fast transient response. Both the switching regulator and linear regulator provide a maximum static regulation tolerance of ±2% over line, load, and temperature ranges. Each output is user-adjustable by means of external resistors.

An integrated soft-start feature brings both supplies into regulation in a controlled manner. Each output is monitored via the FB pins for undervoltage events. If either output drops below 52.5% of the internal reference voltage, both regulators are shutdown.

Applications

• Graphics-GPU and memory supplies
• ASIC power supplies
• Embedded processor and I/O supplies
• DSP supplies