Power controllers seek role in TV

Synchronous buck controller simplifies power management design of LCD TVs and IP set-top boxes that use digital signal processors and FPGAs.

Texas Instruments has introduced a flexible, synchronous buck controller that simplifies power management design of LCD TVs and IP set-top boxes that use digital signal processors (DSPs) and FPGAs.

TI's new TPS40195 high-performance controller provides several features to enhance the power performance of a 4.5 to 20V system.

For instance, the device uses the input voltage available for power conversion as its bias supply, eliminating the need for additional voltages to power the integrated circuit.

The TPS40195, which comes in a 16-pin TSSOP, also can switch 180 degrees out of phase when the bi-directional synchronisation pin is used as an output to other buck controllers.

This reduces bulk capacitance and saves board space and cost when using 5 and 12V power supplies.

In addition, the TPS40195 lowers electromagnetic interference (EMI) when the pin is used as an input connected to a master clock.

The controller provides excellent current detection at low duty cycles and limits energy into the system with an over-current sensing feature for both high- and low-side MOSFETs.

The TPS40195 also supports control and protection features, such as shutdown control, power good output, adjustable undervoltage lockout, selectable digital soft start, programmable closed-loop soft start and short-circuit protection.

Power system designers can optimise the TPS40195 for efficiency or solution size by programming the switching frequency from 250 to 600kHz, or the controller can be synchronised via an external clock.

By integrating the bootstrap diode, the device reduces system cost and saves board space.

TI has also introduced the TPS5450, a 5A nonsynchronous step-down convertor if a designer wants to further reduce complexity and external component count in their end-equipment design.

The newest Swift DC/DC convertor integrates a low-resistance, high-side N-channel MOSFET, and provides tight voltage regulation accuracy under transient conditions.

Available in an easy-to-use, eight-pin SOIC PowerPad package, the TPS5450 supports a wide input voltage range of 5.5 to 36V and features a low shutdown quiescent current of 18uA.

The new TPS40195 and TPS5450 controllers are available in volume from TI and its authorised distributors.

Suggested retail pricing per quantities of 1000 units begins at $1.50 each for the TPS40195 and $2.25 each for the TPS5450.

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