Ultra-Small LDO Regulators Boast Ultra-Low Power Drain

With extremely low quiescent currents and space-saving footprints, six new CMOS low-dropout (LDO) voltage regulators are designed to provide accurate, stable, clean and quiet voltage to sub-systems ranging from 1.5V to 5.0V. The NCP551, NCP552, NCP553, NCP561, NCP562 and NCP563 are said to be ideal for implementation in battery-powered handheld electronics and portable instrumentation. These new devices deliver quiescent currents ranging from 2.5 to 3.0 µA. In addition, with a maximum input of 12V, the NCP55x series is better equipped to handle applications with multiple lithium battery cells than devices with maximum inputs of only 6V, the company says. The NCP56x series, however, does offer designers 6V maximum input voltage options. An enable pin, specific to the NCP551, NCP552, NCP561, and NCP562 permits added energy savings in the end product by giving the designer the option to turn off portions of the circuitry when idle. Each device contains a voltage reference unit, an error amplifier, a PMOS power transistor, resistors for setting output voltage, and current limit and temperature limit protection circuits. Output voltage accuracy is 2%. Both the NCP55x and NCP56x series of devices feature the ultra-small SC82-AB surface mount package, as well as SOT-23 and TSOP-5 package options. NCP55x devices and the NCP561 are priced at $0.39 each/12,000, while the NCP562 and NCP563 are priced at $0.35. ON SEMICONDUCTOR, Phoenix, AZ. (602) 244-4195.