National Semiconductor Unveils LM5032/34 PWM Controllers

National Semiconductor Corp. (Santa Clara, CA) unveiled its new LM5032 and LM5034 100 V flexible, dual-interleaved, pulse-width modulation (PWM) controllers for conventional single-ended and active clamp reset topologies. The LM5032 and LM5034 controllers can be configured to control either two independently regulated outputs or a single, high-current output from two primary power stages.

In the two-output configuration, the two PWM channels operate 180° out of phase with one another, or are interleaved, which reduces the input ripple current. In the single-output configuration, the interleaving also reduces ripple current in the output filter capacitor. The LM5032 controller can be used for designing dual-interleaved boost, flyback or standard forward converters. The LM5034 controller is specifically designed for interleaved forward converters with active clamp transformer reset.

The LM5032 and LM5034 provide two complete, independent, current-mode PWM controllers with separate soft-start and control pins. Integrated features include a high-voltage start-up regulator that operates over a wide input range of 12 V to 100 V, as well as cycle-by-cycle current limit, slope compensation and over-temperature protection. The LM5032 and LM5034 also feature a fast propagation delay of less than 100 nS and a 2 MHz-capable, single-resistor-adjustable oscillator that can be synchronized externally.

The LM5032, in a TSSOP-16 package, is priced at $1.55 each in 1,000-unit quantities. The LM5034, in a TSSOP-20 package, is priced at $1.90 each in 1,000-unit quantities.