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UNTERPREMSTAETTEN, AUSTRIA: Lowering power consumption is an ongoing struggle for portable devices. Among recent innovations to help designers reach this goal is austriamicrosystems' AS3605 power-management integrated circuit (PMIC). It is designed for portable devices powered by a single-cell Li-Ion battery (see figure). The device integrates seven low dropout regulators (LDOs), a DC/DC converter, a battery charger, a light-emitting-diode (LED) backlight driver, and an audio power amplifier on one die.
According to the company, the features and performance of the AS3605 allow it to be used in many portable devices, such as high-end blood-glucose meters, GPS equipment, mobile meters, high-end remote controls, and e-dictionaries. It also can be used for any entry-level mobile-handset standard including CDMA, WCDMA, GSM, GPRS, EDGE, UMTS, and other American and Japanese standards.
The seven programmable LDOs typically feature noise of 30 V RMS from 100 Hz to 100 kHz. Line/load regulation is below 1 mV static and less than 10 mV transient. The LDOs also provide power-supply rejection of less than 70 dB at 1 kHz. Although the integrated step-down DC/DC converter requires no external Schottky diode, it promises to provide efficiency to 95% over the operating range. In addition, an on-chip low-distortion audio power amplifier provides 1 W at 8 Ω for speaker-phone operation, Hi-Fi ringtones, or other audio uses.