Fairchild Semiconductor – FAN23xx family: TinyBuck® POL Regulators Set Benchmarks for Efficiency, Thermal Performance and System Robustness



Fairchild Semiconductor’s FAN23xx family, the latest generation of TinyBuck regulators, introduces several enhancements that ensure significantly higher efficiency over a very wide load range, and also helps to improve thermal performance and system robustness.

The FAN23xx family consists of integrated point-of-load (POL) regulators that incorporate a constant on-time PWM controller and driver with high side and low side MOSFETs in a single package requiring minimal external components.

To enable end-user applications to achieve increased efficiency, the latest devices have fine-tuned gate-drive circuitry with gate-drive current and dead times optimized for each specific part number. This effectively increases peak efficiency by around 2% compared to competitive solutions. In addition, the regulators feature Fairchild’s constant on-time control architecture with Pulse-Frequency Modulation (PFM), enabling the highest possible light-load efficiency. Constant on-time operation also ensures the regulators have excellent transient response.

The new TinyBuck regulators can operate at up to 1.5MHz switching frequency, enabling high energy efficiency while reducing the number of inductor and capacitor components needed.

In all, there are now 15 device variants, giving designers choices such as 4A, 6A, 10A or 15A output current capability, 4.5V to 15V or 4.5V to 24V input voltage range, and a choice of single voltage operation or regulators designed to operate with a 5V external bias.


  • Programmable soft start
  • Low shutdown current
  • Adjustable sourcing current limit
  • Internal boot diode
  • Thermal shutdown

  • Telecom equipment
  • Storage systems
  • Base stations
  • Enterprise computing
  • PCs
  • Game terminals