LM27966 is a highly integrated charge-pump-based display LED driver from National. The device can drive up to 6 LEDs in parallel with a total output current of 180mA. Regulated internal current sources deliver excellent current and brightness matching in all LEDs. The LED driver current sources are split into two independently controlled groups. The primary group, which can be configured with 4 or 5 LEDs, can be used to backlight the main phone display. An additional, independently controlled led driver is provided for driving an indicator or other general purpose LED function. The LM27966 has an I2C compatible interface that allows the user to independently control the brightness on each bank of LEDs. The device provides excellent efficiency without the use of an inductor by operating the charge pump in a gain of 3/2, or in Pass-Mode. The proper gain for maintaining current regulation is chosen, based on LED forward voltage, so that efficiency is maximized over the input voltage range. The LM27966 is available in National’s small 24-pin Lead- less Leadframe Package (LLP-24).
The LM27966 is a highly integrated charge‑pump‑based white LED driver designed for mobile phone displays, PDAs and general LED lighting. It can drive up to six LEDs in parallel, providing 180 mA total current (30 mA per LED) with 0.3 % current matching and 91 % peak efficiency. The device features an I²C‑compatible interface for independent brightness control of two LED banks (main display and auxiliary).
Key specifications include an input voltage range of 2.7 V to 5.5 V, operation without an external inductor, and a 24‑pin leadless leadframe (LLP‑24) package. The datasheet provides detailed pin descriptions, electrical characteristics, thermal protection, capacitor selection, PCB layout guidelines, and mechanical dimensions for designers.
| Input voltage range | 2.7 V to 5.5 V |
|---|---|
| Total output current | 180 mA (30 mA per LED) |
| Number of LEDs driven | Up to 6 LEDs in parallel |
| Peak LED drive efficiency | 91 % |
| Current matching accuracy | 0.3 % |
| Inductor requirement | No external inductor required |
| Package type | 24‑pin Leadless Leadframe Package (LLP‑24) |
The device can supply up to 180 mA total output current, which can be divided as 30 mA per LED when driving six LEDs.
The LM27966 operates with an input voltage between 2.7 V and 5.5 V.
No, the driver is designed to work without an external inductor.
It can drive up to six LEDs in parallel.