The LM27951 is a switched capacitor white-LED driver capable of driving up to four LEDs
with 30 mA through each LED. Its four tightly regulated current sources ensure excellent LED
current and brightness matching. LED drive current is programmed by an external sense resistor. The
LM27951 operates over an input voltage range from 2.8 V to 5.5 V and requires only four low-cost
ceramic capacitors.
The LM27951 provides excellent efficiency without the use of an inductor by operating the
charge pump in a gain of 3/2, or in a gain of 1. Maximum efficiency is achieved over the input
voltage range by actively selecting the proper gain based on the LED forward voltage
requirements.
The LM27951 uses constant frequency pre-regulation to minimize conducted noise on the
input. It has a fixed 750-kHz switching frequency optimized for portable applications. The LM27951
consumes less than 1 µA of supply current when shut down.
The LM27951 is available in a 14-pin no-pullback WSON package.
For all available packages, see the orderable addendum at the
end of the data sheet.
The LM27951 is a switched capacitor white-LED driver capable of driving up to four LEDs
with 30 mA through each LED. Its four tightly regulated current sources ensure excellent LED
current and brightness matching. LED drive current is programmed by an external sense resistor. The
LM27951 operates over an input voltage range from 2.8 V to 5.5 V and requires only four low-cost
ceramic capacitors.
The LM27951 provides excellent efficiency without the use of an inductor by operating the
charge pump in a gain of 3/2, or in a gain of 1. Maximum efficiency is achieved over the input
voltage range by actively selecting the proper gain based on the LED forward voltage
requirements.
The LM27951 uses constant frequency pre-regulation to minimize conducted noise on the
input. It has a fixed 750-kHz switching frequency optimized for portable applications. The LM27951
consumes less than 1 µA of supply current when shut down.
The LM27951 is available in a 14-pin no-pullback WSON package.
For all available packages, see the orderable addendum at the
end of the data sheet.