ISL6430
Single Sync Buck PWM Controller for Broadband Gateway Applications
Typical Diagram
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
- 1.27V Internal Reference
- ±1% Over Line Voltage and Temperature
- 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-Lead SOIC and 16-Lead QFN
Description
The ISL6430 provides complete control and protection for a DC-DC converter optimized for high-performance broadband gateway applications. It is designed to drive two N Channel MOSFETs in a synchronous-rectified buck topology. The ISL6430 integrates all of the control, output adjustment, monitoring and protection functions into a single package.
The output voltage of the converter can be precisely regulated to as low as 1.27V, with a maximum tolerance of ±1% over temperature and line voltage variations.
The ISL6430 provides simple, single feedback loop, voltagemode 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 ISL6430 protects against over-current conditions by inhibiting PWM operation. The ISL6430 monitors the current by using the rDS(ON) of the upper MOSFET which eliminates the need for a current sensing resistor.
Applications
- Cable Modems, Set-Top Boxes and DSL Modems
- DSP and Core Communications Processor Supplies
- High-Power 5V Input DC-DC Regulators
- Low-Voltage Distributed Power Supplies
