The AS13985 is a new LDO regulator in a wafer level chip-scale package (WL-CSP), which means that the silicon itself is placed directly on the PCB, resulting in a very small package. The device features extraordinarily low noise of only 30 µVRMS between 10 Hz and 100 kHz. This allows the use of a small and less expensive 1-µF ceramic output capacitor. With a supply voltage rejection performance of 60 dB at 1 kHz and 55 dB at 10 kHz, the AS13985 meets the noise requirements for mobile phones and other applications.

A digital enable pin with a turn-on time of only 150 µs allows system-level dynamic power management. Because of a low on-resistance characteristic, the regulator features a voltage drop of only 45 mV at 150 mA output, going down to 0.3 mV at 1 mA. Furthermore, it offers over-temperature and over-current protection. With ensured 150-mA output current and 500-mA peak output current, the AS13985 delivers sufficient power for various applications.

With an operating input voltage between 2.5 V and 5.5 V, the regulator is available in a variety of preprogrammed output voltages from 1.2 to 5 V. The output voltage is regulated with an accuracy of 1%, which meets the requirements of portable battery-powered products. The AS13985 device is available in a 1 mm × 1.4 mm five bumps WL-CSP, which is 15% of the size of a standard SOT23 package.

The AS13985 costs $0.31 in 1,000-piece quantities.

Austriamicrosystems
www.austriamicrosystems.com