ADP1621 is a programmable, high efficiency, low power step-up DC/DC controller that supports external NPN or resistor for high input voltage supply.
The ADP1621 is a fixed‑frequency, pulse‑width‑modulation (PWM) current‑mode step‑up converter controller that drives an external n‑channel MOSFET to raise the input voltage. It can also be used in flyback, SEPIC, and forward topologies, both isolated and non‑isolated.
The handbook provides detailed specifications, pin descriptions, typical application circuits, performance graphs, thermal data, and design guidelines such as component selection, slope‑compensation, and synchronization methods.
| Input voltage range | 2.9 V to 5.5 V |
|---|---|
| Operating frequency range | 100 kHz to 1.5 MHz |
| Internal soft‑start time | 2048 cycles |
| Thermal shutdown temperature | 150 °C |
| Efficiency | up to 92 % |
The device operates from 2.9 V up to 5.5 V, and can accept as low as 1 V for special low‑power applications.
A resistor connected to the FREQ pin sets the free‑running frequency between 100 kHz and 1.5 MHz, and the frequency can be synchronized to an external clock via the SDSN pin.
The ADP1621 provides current‑limit, thermal shutdown at about 150 °C, undervoltage lockout, shutdown input, and ESD protection.