The ISL8117 and ISL8117A from Intersil are synchronous buck controllers which feature a wide input-voltage range, and offer an output-voltage capability up to 54V suitable for driving a string of LEDs.
The controllers use the valley current-modulation technique to provide an easy-to-implement power-supply design which requires only a small number of external components.
The 4mm x 4mm ISL8117 and ISL8117A feature programmable softstart and enable functions and a powergood indicator for ease of supply-rail sequencing and to support other housekeeping requirements. In some situations, a complete power-supply circuit based on the ISL8117/ISL8117A can be designed with just ten external components, while providing over-voltage, over-current and over-temperature protection.
The devices use settings of a single resistor for configuring functions such as operating frequency and over-current protection. Their low-ripple diode-emulation mode with pulse skipping at light loads dramatically lowers stand-by power consumption, while providing consistent output ripple at various load levels.
The ISL8117A is a derivative of the ISL8117 which replaces its Clkout pin with a Comp pin to provide flexibility to users who wish to configure the voltage loop compensation externally.
- Current-mode control with input-voltage feed-forward
- Input-voltage range: 4.5V to 60V
- Output-voltage range: 0.6V to 54V
- Programmable soft-start
- Programmable frequency range: 100kHz to 2MHz
- LED panels
- PLC and factory automation
- Security surveillance
- Server and data centres
The ISL8117DEMO1Z and ISL8117DEMO2Z demonstration boards are designed for high-current applications using the ISL8117 buck controller. The current rating is limited by the FETs and inductor selected, but the ISL8117’s gate driver is capable of delivering up to 20A for the buck output.
Orderable Part Number: ISL8117DEMO1Z and ISL8117DEMO2Z