The ADP1821 is a versatile and inexpensive, step-down DC-to-DC controller from Analog Devices. It features a wide power-input voltage range, wide output voltage range, low cost, fixed-frequency operation, no current sense resistor required, programmable soft start with reverse current protection, soft start, thermal overload, current-limit protection, undervoltage lockout, and small, 16-lead QSOP package.
The ADP1821 step‑down controller from Analog Devices provides a synchronous PWM voltage‑mode regulation solution for high‑power applications. It operates from a 1 V‑24 V input and can generate output voltages as low as 0.6 V up to 85 % of the input voltage. The device is available in a 16‑lead QSOP package and supports fixed switching frequencies of 300 kHz or 600 kHz, with optional synchronization up to 1.2 MHz.
Key protection functions include soft‑start, thermal overload, current‑limit, undervoltage lockout, and a power‑good output. The controller is designed for use in telecommunications, servers, medical imaging, and other high‑performance systems, operating over a –40 °C to +125 °C temperature range.