DC/DC buck converter shrinks PCB space in point-of-load applications

By Majeed Ahmad, contributing writer

Silanna Semiconductor has announced a new family of synchronous point-of-load (PoL) buck converters that aims to facilitate high power density and efficiency as well as low power loss for demanding applications in enterprise servers, telecommunications, and networking equipment.

The SZPL8216A devices integrate a DC/DC constant-on-time (COT) controller, output gate drivers, and output power blocks in a 3 × 4-mm QFN package. They deliver up to 12 A with 94% peak efficiency when converting from a nominal 12-V input down to a 0.6-V to 5.5-V output voltage range.

These synchronous PoL buck converters feature a selectable switching frequency — 600 kHz to 1 MHz — which allows developers to make design-specific decisions to optimize component size versus efficiency. The ability to operate at 1 MHz also enables designers to use a smaller output filter and thus minimize the printed-circuit-board (PCB) size.

Moreover, the SZPL8216A DC/DC buck converters feature programmable current limit and soft start time, remote output voltage sensing, and pre-biased startup. The buck converter allows designs to operate from a single supply using the internal LDOs, or designers may bypass them and instead use an external 3.3-V or 5-V bias supply to increase conversion efficiency further.

The family includes three different versions, with different fault mode behaviors, voltage references, and AVCC operating voltages:

• SZPL8216A-AE34: latched fault mode; VREF 0.9 V; AVCC 3.3 V
• SZPL8216A-BE34: hiccup fault mode; VREF 0.6 V; AVCC 3.3 V
• SZPL8216A-CE34: hiccup fault mode; VREF 0.6 V; AVCC 5.0 V

Sample quantities and an evaluation PCB are available now. The devices are priced at $0.86/1,000 pieces and will be available in mass production in Q3.