PWR 5303 Texas Instruments DC/DC Converter

The Texas Instruments / Power Convertibles PWR53XX Series DC/DC Converters is a family of wide input range DC/DC converters that accept either 9.2 to 18VDC, 18 to 36VDC, or 36 to 72VDC depending on the model selected. A fixed-frequency, 200kHz-driven, push-pull oscillator input stage is used to ensure predictable and controlled performance. This eliminates the high peak voltages or currents present in other topologies, which reduce reliability.

A two-section pi-filter is used in the input stage to reduce reflected ripple current to a typical level of 30mAp-p. The design of this filter network also ensures stable frequency response of the PWR53XX Series, regardless if input voltage or output load current. Six-sided shielding suppresses electromagnetic radiation, which may disturb sensitive analog measurements or interfere with system timing signals.

All PWR53XX models will operate safely even at no load up to a temperature of 55 Degrees Celsius, although there is a minimum load established for regulation measurements.

The controller used in the input stage of the PWR53XX Series has been designed to provide cycle-by-cycle current limiting for continuous short-circuit protection. In addition, it features soft-start, maximum duty cycle control, under-voltage lockout, and fully latched logic, which incorporates double pulse suppression. These features guarantee controlled, predictable operation to enhance unit reliability even under adverse operating conditions.

Rugged MOSPOWER transistors permit higher frequency operation (200kHz) with less complicated drive circuitry than is possible with bipolar power transistors. Reduced parts count adds to the PWR53XX Series reliability.

The PWR53XX Series offers exceptional line and load regulation over the full input voltage and output load current range and not just some fractional portion. The output stage of the PWR53XX Series is designed to solve the problems associated with closing a control loop across a voltage isolation barrier. It is a more stable and reliable alternative to a simple optical coupler. Transformer isolation between the output stage and the input oscillator preserves barrier isolation without the degradation over that is inherent with some optical couplers. The voltage reference and gain stage of this output circuit makes it possible for the PWR45XX to offer such exceptionable regulation.