Date: 27/01/2011

LDO features low quiescent current of 210 micro amps and PSRR of 60 dB

Analog Devices, Inc. has unveiled two low-quiescent-current LDOs (low-dropout linear regulators) ADP124 and ADP125 LDOs with very good PSRR (power-supply-rejection ratio) performance of 60 dB at 100 kHz. (ADI claims this value is double that of the nearest competing LDO), and low noise of 35 µVrms (micro-volts per root mean squared) at 1.8 V output. Another highlight of these LDOs are they feature low quiescent current of 210 µA and a 130 mV dropout voltage at a 500 mA. ADP124 and ADP125 operate from an input voltage between 2.3 V and 5.5 V and deliver up to 500 mA of output current down to a 0.8 V voltage output.

"Designing for portable products requires a small solution size, low power dissipation, and high power-supply rejection for the best mixed-signal processing performance, particularly during instances where the power supply is a hidden source of noise," said Walt Heinzer, product line manager, Power Management Group, Analog Devices. "By offering a superior 60-dB PSRR, these high-performance LDOs are 30 dB--or 30X better on a logarithmic scale--when compared to commodity LDOs that offer 25 dB or 30 dB. They surpass competitive alternatives by offering the best combination of very-low dropout, low noise, and high power-supply-rejection ratio at a very competitive price."

The ADP124 offers 31 fixed-output voltage options from 1.75 V to 3.3 V. The ADP125 LDO provides an adjustable output voltage between 0.8 V and 5.0 V using an external voltage divider. The ADP124 and ADP125 are specifically designed for stable operation with tiny 1 µF ceramic input and output capacitors to meet the requirements of high-performance, space-constrained applications. The LDOs are available in a compact 2 mm x 2 mm x 0.55 mm LFCSP package or an 8-lead exposed paddle MSOP package.

Both the devices provides tight tolerances for core voltage rails in FPGA applications and are stable with 1 µF Cout ceramic capacitors.

Availability: Now
Price: Each $0.42 per 1K units
Package: 3 mm x 5 mm 8-Lead EP MSOP and 2 mm x 2 mm LFCSP-8

Editorial Product Rating: ** (Average Plus) This device delivers excellent performance though many applications may not need this level of power purity and efficiency.