The SP6121 is a fixed frequency, voltage mode, synchronous PWM controller designed to work from a single 5V or 3.3V input supply, providing excellent AC and DC regulation for high efficiency power conversion. The operating frequency is internally set at 500kHz, permitting the use of small, surface mount inductors and capacitors. Requiring only few external components, the SP6121 packaged in an 8-pin SOIC, is especially suited for low voltage applications where cost, small size and high efficiency are critical.
The SP6121 is a constant‑frequency, voltage‑mode, synchronous PWM controller designed for low‑voltage DC‑DC step‑down converters. It operates from a single 3 V‑5.5 V supply and uses an internal 500 kHz oscillator, enabling small external components and high efficiency.
Key features include a 0.4 V/ms soft‑start, programmable output voltage, lossless adjustable current limit, over‑voltage and over‑current protection, and a high‑side PMOS driver that eliminates the need for a charge pump. The device is packaged in an 8‑pin SOIC and is suited for applications such as video cards, board‑level supplies, and distributed power systems.
| Input voltage range (Vcc) | 3.0 V to 5.5 V |
|---|---|
| Internal oscillator frequency | 500 kHz |
| Quiescent supply current (Vog) | 0.5 mA to 1.0 mA |
| Maximum duty cycle | 100 % |
| Minimum duty cycle | 0 % |
| Soft‑start slew rate | 0.4 V/ms |
| Shutdown threshold voltage | 0.2 V to 0.4 V |
The internal oscillator sets the PWM frequency at 500 kHz.
It operates with a supply voltage (Vcc) between 3.0 V and 5.5 V.
The controller includes an internal soft‑start circuit with a slew rate of 0.4 V/ms.
The SP6121 can operate up to a 100 % duty cycle.