New Industry Products

Versatile 12A 1MHz Buck Converter for Ultra-Compact PoL PCB Layout

June 25, 2019 by Paul Shepard

Silanna Semiconductor announced its highly integrated SZPL8216A family of synchronous point-of-load (PoL) buck converters. These dc-dc buck converters integrate the functions of the dc-dc constant-on-time (COT) controller, output gate drivers and output power blocks all in one compact 3mm x 4mm QFN package to deliver the best power density with a minimum external component count.

The devices enable designers to achieve ultra-compact PCB layout, high power density and high efficiency for low power loss in demanding and space-constrained applications such as enterprise servers, telecommunications, and networking equipment.

The SZPL8216A-A, SZPL8216A-B and SZPL8216A-C family of devices delivers up to 12 Amps with 94% peak efficiency when converting from a nominal 12V input down to a 0.6V to 5.5V output voltage range. Providing design versatility, the devices feature a selectable switching frequency, 600kHz to 1MHz, allowing users to make design-specific decisions to optimize their component size versus efficiency. With the ability to operate at 1MHz, designers can use a smaller output filter to minimize their total PCB solution size.

Other features include programmable current limit and soft start time; remote output voltage sensing; pre-biased start-up and a full suite of robust power supply protection features including UVLO/OCP/OVP/UVP and OTP. Providing additional design versatility, the devices may operate from a single supply using their internal LDOs, or designers may bypass them and instead use an external 3.3V or 5V bias supply to increase conversion efficiency further.

SZPL8216A synchronous PoL buck converters.

The SZPL8216A COT controlled devices employ Silanna's proprietary S-Loop™ control architecture which provides near instantaneous response to load transitions with minimal increase in overshoot or undershoot. Such performance is critical for multi-core CPU and FPGA applications that quickly power on and off with high current load transients and require a very stable power supply voltage.

Key Specifications:

  • Ultra-compact QFN 3mmx4mm package
  • 94% peak efficiency
  • Up to 1MHz switching frequency
  • 5V to 16V input voltage range
  • 6V to 5.5V output voltage range

Key Features:

  • Proprietary S-Loop control and adaptive COT architecture for fast load transient response
    • All ceramic output capacitor solution
  • Programmable current limit
  • Internal LDO for MOSFET driver bias
  • Output tracking with external reference input
  • UVLO/OCP/OVP/UVP/OTP protections
  • Pre-bias startup with programmable soft start time
  • Diode emulation mode for light load efficiency boost


The family includes three different versions, all packaged in the same 21-lead, 3mmx4mm QFN package, allowing for different fault mode behaviors, voltage references, and AVCC operating voltages:

  • SZPL8216A-AE34: Latched Fault Mode; VREF 0.9V; AVCC 3.3V
  • SZPL8216A-BE34: Hiccup Fault Mode; VREF 0.6V; AVCC 3.3V
  • SZPL8216A-CE34: Hiccup Fault Mode; VREF 0.6V; AVCC 5.0V

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