Texas Instruments claims that their TPS54A20 SWIFT synchronous DC/DC converter has industry's highest current density for a nominal 12-V input device, at 50 A/cm3. This 10-A converter operates at up to 5 A per phase without special magnetic components or need for compound semiconductors such as GaN devices. It combines a unique two-phase, series-capacitor DC/DC buck topology that merges a switched-capacitor circuit with a multiphase buck converter. It targets space- and height-constrained point-of-load (POL) telecom and networking power-supply designs. Input range for this buck (step-down) converter is 8 to 14 V while output can be set between 0.5 V and 2 V.
Among the key attributes of the TPS54A20 are:
•small overall size, due to its quad flat no-lead packaging and use of inexpensive, tiny 2-to-5 MHz inductors, for a 131-mm2 total footprint size that needs 50 percent less area than existing solutions
•low profile, and with its height of under 2 mm, it can be placed on the back side of a printed-circuit board (PCB)
•Multi-MHz operation with a 14-ns minimum on-time compatible 4-to-10 MHz switching, yet without compromising efficiency or electromagnetic interference (EMI) performance
The TPS54A20 converter is available in a 20-pin, 3.5 mm × 4 mm × 1mm thermally enhanced QFN package, and is priced at US$3.25 (1,000-unit quantities); an evaluation module is available for performance assessment.
Intersil has introduced a pair of pin-compatible 5-A and 3-A power modules for lower output currents, intended for line and battery-powered industrial and high-end consumer applications. These high power density modules feature to 95% efficiency in a compact 4.5 mm × 7.5 mm × 1.85 mm footprint. The modules are complete power supplies that include a controller, MOSFETs, inductor and passive components inside an encapsulated package, simplifying system design. Switching frequency is user adjustable from 680 kHz to 3.5 MHz.
With just sub-2 mm height, the ISL8205M and ISL8202M can also mounted on the back of a PCB, as with the TI units. Both converters accept input voltages from 2.6 V to 5.5 V and provide an adjustable output voltage down to 0.6V. Pin compatibility between the two modules lets engineers migrate, if needed, from 3 A output current to the higher 5-A output rating. The units also offer selectable light-load efficiency, 100% duty cycle modes, and 50 µA quiescent-current enable.
Due to their efficiency and copper lead-frame structure, the modules operate at full load over a wide temperature range with no airflow or heat sinks. Fault protection covers input under-voltage lockout, over-temperature, over-current/short-circuit with hiccup mode, over-voltage and negative over-current. Further, programmable soft-start reduces inrush current, and automatic output discharge ensures a soft stop for eliminating current-based transients.
Both modules are packaged in 22-lead QFN package. The 5-A ISL8205M is priced at US$3.79, while the 3-A ISL8202M is US$2.79 (1,000-unit quantities). Intersil also offers $69 evaluation boards for each module.
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