The L4971 is a 1.5A step-down switching regulator with an input voltage range of 8V to 55V and an output voltage range of 3.3V to 50V. The output voltage can be adjusted using an external divider. The device is fabricated in BCD mixed technology, using an internal power D-MOSFET (with a typical Rdson of 0.25 Ω) to achieve very high efficiency and high switching speed. A switching frequency up to 300KHz is possible (the maximum power dissipation of the packages must be observed). A wide input voltage range of 8V to 55V and output voltages regulated from 3.3V to 50V cover the majority of today’s applications. Features of this new generations of DC-DC converter include pulse-by-pulse current limit, hiccup mode for short circuit protection, voltage feedforward regulation, soft-start, protection against feedback loop disconnection, inhibit for zero current consumption and thermal shutdown. The device is available in plastic dual in line, DIP8 for standard assembly, and SO16W for SMD assembly.
The L4971 is a monolithic step‑down switching regulator that delivers up to 1.5 A over an output range of 3.3 V to 50 V. It operates from an input voltage of 8 V to 55 V and features an internal power D‑MOS transistor for high efficiency and fast switching. The device includes a range of protection functions such as pulse‑by‑pulse current limiting, hiccup mode, voltage feed‑forward, soft‑start, inhibit for zero‑current consumption and thermal shutdown.
The regulator is offered in DIP‑8 and SO‑16W packages and provides a selectable switching frequency up to 300 kHz. Typical performance on an evaluation board shows efficiencies up to 85 % at 3.3 V output and 1.5 A load, with low line and load regulation. Detailed electrical characteristics, pin descriptions and absolute maximum ratings are provided for design integration.
| Input voltage range | 8 V to 55 V |
|---|---|
| Output voltage range | 3.3 V to 50 V |
| Maximum output current | 1.5 A |
| Switching frequency (adjustable) | up to 300 kHz |
| Package types | DIP‑8, SO‑16W |
| Thermal shutdown | Yes |
| Soft‑start function | Yes |
The L4971 can operate with an input voltage up to 55 V.
The output voltage is adjustable from 3.3 V to 50 V.
Yes, the device features a soft‑start function.