STMicroelectronics introduces a pair of compact mono audio amplifiers for driving 16 to 32O speakers and ear-pieces in cellular and cordless phones, personal digital assistants and other portable appliances. The TS419 and TS421 are available in MiniSO-8 and DFN8 packages. The parts will operate from a supply of 2 V and draw a maximum of 2.5 mA. Standby current consumption can be as little as 10 nA. Standby mode can be active high for the TS419 or active low for the TS421. The parts can be ordered with an external gain configuration or with fixed gain of 6, 12, 18 dB. They also have On/Off click reduction circuitry. With a Vcc of 5 V the parts offer a typical output power of 295 mW into 16Ω, at a total harmonic distortion plus noise (THD + N) figure of 1% maximum. With a 32Ω load, output power is 207 mW. With a Vcc of 3.3 V the parts offer a typical output power of 113 mW into 16Ω, at a total harmonic distortion plus noise (THD + N) figure of 1% maximum. With a 32Ω load, output power is 81 mW. The signal to noise ratio for the parts is typically 98 dB(A) with a 5 V supply. The power supply rejection ratio (PSRR) figure typically 56 dB at 1kHz, with the inputs grounded.