New Industry Products

Intersil Announces PWM Controllers that Integrate MOSFET Drivers

November 27, 2006 by Jeff Shepard

Intersil Corp. introduced the ISL6545 and ISL6545A single-output PWM (pulse width modulation) controllers. These devices integrate the boot diode and current-sensing functions, reducing the number of external components required.

The ISL6545 and ISL6545A allow a lower BOM cost by integrating the boot diode, the overcurrent protection, and the MOSFET drivers onto a single chip. The overcurrent function protects the controllers from a shorted output by using the lower MOSFET's on-resistance, rDS(ON), to monitor the current, enhancing the efficiency of the controllers and reducing cost by eliminating the current- sensing resistor.

"Intersil's small form factor ISL6545 and ISL6545A provide maximum performance and reliability for today's power applications," said Philip Chesley, Marketing Manager of Intersil's Desktop Power Products Group. "The wide input range (1.0 to 12V) of these devices provides design flexibility, while the wide voltage output range (0.6V to VIN) allows them to be used in a broad range of applications."

The ISL6545 and ISL6545A make implementation of a complete control and protection scheme for a dc-dc step-down converter driving inexpensive N-channel MOSFETs in a synchronous buck topology simple. A fixed frequency oscillator (300kHz for ISL6545; 600KHz for ISL6545A) reduces design complexity while reducing typical application cost and increasing efficiency, allowing these devices to be used in small form factor applications.

These devices provide a single feedback loop and voltage-mode control with fast transient response. The output voltage can be precisely regulated to as low as 0.6V with a maximum tolerance of +1.0% over temperature and line voltage variations. The error amplifier of the ISL6545 and ISL6545A feature a 20MHz gain bandwidth product and 9V/µs slew rate that enables high converter bandwidth for fast transient performance. The resulting PWM duty cycles range from 0% to 100%. A fixed internal soft start, capable into a pre-biased load allows a controlled monotonic soft start.

The ISL6545 and ISL6545A are available now in an 8-lead SOIC package and are priced at $1.00 each and in a 10-lead QFN package, priced at $1.51 each in 1,000-unit quantities.