ISL9443
Triple, 180° Out-of-Phase, Synchronous Step-Down PWM Controller
Key Features
- Three Integrated Synchronous Buck PWM Controllers
- Internal Bootstrap Diodes
- Independent Programmable Output Voltage
- Independent Soft-Starting and Tracking
- Power-Good Indicator
- Light Load Efficiency Enhancement
- Low Ripple Diode Emulation Mode with Pulse Skipping
- Supports Pre-Biased Output
- Programmable Frequency: 200kHz to 1200kHz
- Adaptive Shoot-Through Protection
- Out-of-Phase Switching (0°/180°/0°)
- No External Current Sense Resistor
- Uses Lower MOSFET's rDS(ON)
- Complete Protection
- Overcurrent, Overvoltage, Over-Temperature
- Wide Input Voltage Range: 4.5V to 28V
- Pb-Free (RoHS Compliant)
Description
The ISL9443 is a triple-output synchronous buck controller that integrates three PWM controllers which are fully featured and designed to provide multi-rail power for use in products such as cable and satellite set-top boxes, VoIP gateways, cable modems, and other home connectivity products as well as a variety of industrial and general purpose applications. Each output is adjustable down to 0.7V. The PWMs are synchronized at 180° out-of-phase, thus reducing the input RMS current and ripple voltage.
The ISL9443 offers programmable soft-start and tracking functions for ease of supply rail sequencing and integrated UV/OV/OC/OT protections in a space conscious 5mmx5mm QFN package.
Switching frequency can be set between 200kHz and 1200kHz using a resistor. The ISL9443 can be synchronized to an external clock to reduce beat frequencies.
The ISL9443 utilizes internal loop compensation to keep minimum peripheral components for a compact design and a low total solution cost. The controller is implemented with current mode control with feed forward to cover various applications even with fixed internal compensation.
Applications
- VoX Gateway Devices
- NAS/SAN Devices
- ATX power supplies


