Sub-microamp quiescent current LDOs extend battery life in wireless devices

NORWOOD, USA: Analog Devices Inc. (ADI), a global leader in high-performance semiconductors for signal-processing applications, has introduced four low-dropout regulators (LDOs) that address the size, power dissipation and power-supply-rejection requirements of wireless mobile devices.

The ADP160, ADP161, ADP162 and ADP163 ultra-low-quiescent-current LDOs extend the battery life of portable devices by drawing only 560 nA (typical) at no load and 42 μA of quiescent current (typical) at full load. These LDOs provide superior 70 dB PSRR (power-supply-rejection ratio) at 60 Hz, which is more than twice that of competing LDOs at full load current.

The new ADP16x series LDOs are designed for applications such as power meter reader/data terminals, portable industrial, medical measurement devices and remotely located equipment operating from batteries or solar power.

The ADP160, ADP161, ADP162 and ADP163 LDOs provide up to 150 mA of output current and operate from 2.2-V to 5.5-V supplies. The ADP160 and ADP162 fixed-output voltage and ADP161 and ADP163 adjustable-output voltage regulators are available in TSOT (thin–small-outline transistor) packages, while the ADP160 and ADP162 are additionally available in WLCSP (wafer-level, chip-scale package) packages.

The ADP160 and ADP161 also include an output switch to discharge the output load capacitor to zero volts when the device is turned OFF to ensure microcontrollers are in a known state for restart.

“Using innovative design techniques, the ADP16x LDO series provides both ultra-low quiescent current and superior power-supply-rejection performance for digital and RF applications,” said Walt Heinzer, product line manager, Power Management Group, Analog Devices, Inc. “These new LDOs are optimized for use with small, 1 μF ceramic capacitors and will meet the requirements of high-performance, space-constrained designs.”

Key features and benefits:
* Ultra-low quiescent current extends battery life especially during standby operation.
* Power-supply-rejection ratio of 70 dB at 100 Hz limits AC-input ripple during battery charging.
* Stability with small 1 µF ceramic output capacitor enables very compact designs when combined with the ADP162 LDO in a 1 mm x 1 mm WLCSP package.
* An initial accuracy of ±1 percent meets the needs of 1.8 V, 1.5 V and 1.2 V systems.