ISL6525
Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller
Key Features
- Drives Two N-Channel MOSFETs
- Operates From +5V or +12V Input
- Simple Single-Loop Control Design
- Voltage-Mode PWM Control
- Fast Transient Response
- High-Bandwidth Error Amplifier
- Full 0% to 100% Duty Ratio
- Excellent Output Voltage Regulation
- 1.20V Internal Reference
- ±1% Over Line Voltage and Temperature
- Programmable delay for PGOOD signal
- Over-Current Fault Monitor
- Does Not Require Extra Current Sensing Element
- Uses MOSFETs rDS(ON)
- Small Converter Size
- Constant Frequency Operation
- 200kHz Free-Running Oscillator Programmable from 50kHz to Over 1MHz
- 14 Pin, SOIC Package
- Pb-Free Available (RoHS Compliant)
Description
The ISL6525 provides complete control and protection for a DC-DC converter optimized for high-performance microprocessor applications. It is designed to drive two N Channel MOSFETs in a synchronous-rectified buck topology. The ISL6525 integrates all of the control, output adjustment, monitoring and protection functions into a single package. A programmable delay time for the PGOOD signal makes it especially suitable for the VTT regulation in VRM8.5 applications. The output voltage of the converter can be precisely regulated to as low as 1.20V, with a maximum tolerance of ±1% over temperature and line voltage variations.
The ISL6525 provides simple, single feedback loop, voltage-mode control with fast transient response. It includes a 200kHz free-running triangle-wave oscillator that is adjustable from below 50kHz to over 1MHz. The error amplifier features a 15MHz gain-bandwidth product and 6V/µs slew rate which enables high converter bandwidth for fast transient performance. The resulting PWM duty ratio ranges from 0% to 100%.
The ISL6525 protects against over-current conditions by inhibiting PWM operation. The ISL6525 monitors the current by using the rDS(ON) of the upper MOSFET which eliminates the need for a current sensing resistor.
Applications
- Power Supply for Various Microprocessors
- VTT Regulation for VRM8.5
- High-Power 5V to 3.xV DC-DC Regulators
- Low-Voltage Distributed Power Supplies
