The ADP2121 is a high frequency synchronous step-down DC-DC converter with 92% peak efficiency, 6 MHz operating frequency, 38 μA (typical) no load quiescent current in PFM mode, fixed output voltages of 1.80 V, 1.82 V, 1.85V, 1.875V, and continuous output current of 500 mA. It accepts input voltages from 2.3 V to 5.5 V and features various protections and an ultra small size. Suitable for applications such as mobile phones, digital cameras, digital audio, and portable equipment.
The ADP2121 is a high‑frequency, low‑quiescent‑current step‑down converter designed for portable applications where board area and battery life are critical. It operates from a 2.3 V to 5.5 V input and provides up to 500 mA continuous output at fixed voltages of 1.80 V, 1.82 V, 1.85 V or 1.875 V. The device features synchronous rectification, automatic mode selection between PWM and PFM for optimal efficiency, and a soft‑start circuit.
The datasheet includes detailed specifications, pin‑out descriptions, typical application circuits, PCB layout guidelines, and ordering information. Protection functions such as output‑to‑ground short‑circuit protection, current‑limit, undervoltage lockout, and thermal shutdown are built‑in to safeguard both the converter and external components.
| Continuous output current | 500 mA |
|---|---|
| Peak efficiency | 92 % |
| Operating frequency | 6 MHz |
| Fixed output voltage options | 1.80 V, 1.82 V, 1.85 V, 1.875 V |
| Shutdown supply current | 0.28 pA (typical) |
| Thermal shutdown threshold | 150 °C |
| Undervoltage lockout threshold (rising) | 2.2 V |
It can supply up to 500 mA of continuous output current.
The device offers fixed output options of 1.80 V, 1.82 V, 1.85 V, or 1.875 V.
It includes output‑to‑ground short‑circuit protection, current‑limit protection, undervoltage lockout, thermal shutdown, and a soft‑start circuit.