High ripple rejection for LDO regulators

Edited by the Electronicstalk editorial team Nov 2, 2001

Seiko Instruments has a series of low-current LDO voltage regulators with high ripple rejection ratio.

Seiko Instruments has a series of low-current LDO voltage regulators with high ripple rejection ratio.

The high ripple rejection ratio makes the S-L2980 a series of low-noise LDO voltage regulators, which makes it perfect for use in wireless RF devices and cellphones.

The low quiescent current of 0.1uA (1uA max at power off) makes it ideal for PDAs, MP3 players and other portable electronic equipment.

It is known that LDO voltage regulators need an output capacitor.

But, the S-L2980 was designed for use with ceramic capacitors, although tantalum and electrolytic capacitors can also be used.

Some of the benefits of a ceramic versus a tantalum capacitor include smaller size, better safety (tantalum can burn, ceramic won't), lower ESR (equivalent serial resistance), and lower cost.

The S-L2980 Series has an output voltage range of 1.5 to 6.0V at 0.1V increments.

Other features of the S-L2980 include a low dropout voltage of 120mV at 50mA for a 3.0V output; output voltage accuracy of 2.0%; high peak current capability of 150mA at Vin Vout(S) + 1V; a ripple rejection ratio of 70dB at 1kHz; and a built-in power-off circuit.

The S-L2980 comes in 5-pin SON(A) (2.0 x 2.1 x 0.85 mm) or SOT-23-5 (2.9 x 2.8 x 1.3mm) packages.