The LM2771 is a switched capacitor step-down regulator that produces a 1.5V output without the use of an inductor. It is capable of supplying loads up to 250mA. The LM2771 operates with an input voltage from 2.7V to 5.5V, and requires only 3 low-cost ceramic capacitors. The LM2771 uses a regulated 0.5x charge pump to give power conversion efficiencies nearly twice as high as an LDO. Pre-regulated 1.1MHz fixed-frequency switching results in very low ripple and noise on both the input and the output. When output currents are low (<30mA typ.), the part automatically switches to a low-ripple PFM regulation mode to maintain high efficiency over the entire load range. At input voltages below 3.5V (Typ), the charge pump goes into pass mode, with efficiencies similar to an LDO. The LM2771 is available in National’s 10-pad Leadless Leadframe No-Pullback Package (LLP-10).
The LM2771 is a switched‑capacitor step‑down regulator that produces a 1.5 V output without an inductor, supporting input voltages from 2.7 V to 5.5 V and delivering up to 250 mA. It uses a 0.5× charge pump and a fixed 1.1 MHz switching frequency to achieve high efficiency (up to 81 %) and very low output ripple (8 mV @250 mA).
The device is supplied in a 10‑pad leadless leadframe (LLP‑10) package (3 mm × 3 mm × 0.8 mm) and requires three external low‑ESR ceramic capacitors. Detailed electrical characteristics, pin descriptions, layout guidelines, and recommended capacitor configurations are provided for designers.
| Output Voltage | 1.5 V |
|---|---|
| Maximum Output Current | 250 mA |
| Input Voltage Range | 2.7 V to 5.5 V |
| Switching Frequency | 1.1 MHz |
| Efficiency (250 mA load) | 81 % |
| Output Ripple (250 mA) | 8 mV |
| Package | LLP‑10 (3 mm × 3 mm × 0.8 mm) |
The LM2771 provides a regulated 1.5 V output.
It can supply up to 250 mA of output current.
The device operates at a fixed 1.1 MHz switching frequency.
It is offered in a 10‑pad leadless leadframe (LLP‑10) package measuring 3 mm × 3 mm × 0.8 mm.