Stackable DC/DC controller eyes high-density servers

Texas Instruments Inc. introduces a single-channel version of its TPS40KTM stackable controller family that transforms power supplies in data centers and telecommunications equipment into fully scalable, interleaved power systems with higher performance and design flexibility.

TI's TPS40180 synchronous, DC/DC controller allows a system designer to connect or "stack" together multiple power modules, resulting in a high-density power supply that supports 10-200A of output current. Based on the TPS40140 dual-phase controller announced in 2006, the single-channel version provides greater design flexibility when additional circuitry or daughter cards are added to the board—especially when the dual-phase capabilities of the TPS40140 are not needed.

TPS40180 features automatic phase-balancing, which allows a power supply to minimize the ripple current in both the output and input capacitors and results in an overall smaller solution size. Designers can also implement topologies where multiple output rails can be synchronized to achieve greater levels of power density and flexibility, while minimizing EMI system noise. The load share feature enables modular power supply design where modules can be paralleled together, so that each module will deliver power equally to the load.

The TPS40180 device supports a wide input voltage conversion range of 2-40V and operates from a 4.5V to 15V power source. The device converts from 15V input to 0.7V output at a programmable switching frequency of 1MHz per phase, resulting in an effective ripple frequency of up to 8MHz at the input and output during operation. TPS40180 also has excellent line and load regulation of 0.1 percent, supported by a high-precision ±0.5 percent, 0.7V voltage reference and high-accuracy differential load sense amplifier.

TPS40180 is equipped with complete supervisory and control features for today's power supplies, including pre-bias start-up capability, programmable under-voltage lockout, lossless direct current resistance or resistor current sensing, power good, soft start control, synchronization input, programmable over-current protection and thermal shutdown. Moreover, the controller provides a unique eTrim feature that allows a designer to trim the reference voltage on the device to compensate for external component tolerances. This helps tighten overall system accuracy and specifications for output voltage of the converter.

The TPS40180 controller is available in volume from TI and its authorized distributors. Packaged in a 4-by-4mm, 24-pin QFN housing, suggested resale pricing is $1.95 each in quantities of 1,000 units. Evaluation modules of the TPS40180 and TPS40140, application notes, reference designs and TI's Power Management Selection Guide are available at