New Industry Products

IR Intros IR3637SPbF and IR3637ASPbF PWM Controllers

October 05, 2005 by Jeff Shepard

International Rectifier Corp. (IR, El Segundo, CA) introduced two 1-percent accurate, single-output, synchronous buck, pulse-width modulated (PWM) controllers with 4.5 V to 16 V input-voltage capability. The new IR3637SPbF and IR3637ASPbF are compact and simple solutions for up to 15 A dc-dc point-of-load applications such as dual data rate (DDR) memory, field-programmable gate arrays (FPGAs), and video graphics processors. Combined with its selection of power MOSFETs, the two controllers offer design flexibility and improved performance versus integrated solutions.

The two PWM controllers feature a 0.8 V, 1-percent accurate voltage reference. In next-generation systems, peripheral rails can require as little as 3-percent total voltage error tolerance to ensure data signal integrity. Both ICs include short-circuit protection, input under-voltage lockout, and an externally programmable soft-start function. The devices are available in the standard SO-8 package.

The IR3637SPbF operates at 400 kHz, suitable for output currents up to 15 A for applications such as desktop motherboard peripheral rails (DDR memory and chipset power). The IR3637ASPbF runs at 600 kHz and provides optimum efficiency in applications requiring less than 7 A (FPGAs). The 600 kHz operating frequency reduces required inductor size when compared to lower-frequency solutions, and increases control loop bandwidth for improved transient response. Both PWM controllers are suitable for general-purpose dc-dc conversion in a variety of other switching power supply applications.

Pricing for both the IR3637SPbF and the IR3637ASPbF is $0.79 each in 10,000-unit quantities. Both are available in either tubes or tape-and-reel packages. The devices are lead-free and are compliant with the Restriction of Hazardous Substances Directive.