Global Sources
EE Times-India
Stay in touch with EE Times India
EE Times-India > Power/Alternative Energy
Power/Alternative Energy  

Micro PMIC designed for Li-Ion powered devices

Posted: 13 May 2011     Print Version  Bookmark and Share

Keywords:power management  integrated circuit  Li-Ion 

austriamicrosystems rolls out the AS3605, a power management integrated circuit (PMIC) that integrates seven low dropout regulators (LDOs), a DC/DC converter, a complete battery charger, LED backlight driver and an audio power amplifier on one die targeting portable devices powered by a single-cell Li-Ion battery.

The features and performance of the cost-efficient AS3605 Micro PMIC allow it to be used in many portable devices powered by one Li-Ion battery such as high-end blood glucose meters, high-end remote controls, GPS equipment, mobile meters, e-dictionaries and entry-level mobile phones. It can be used for any entry-level mobile phone handset standard, including CDMA, WCDMA, GSM, GPRS, EDGE, UTMS and other American and Japanese standards.

The seven programmable LDOs feature low noise—typically 30µV RMS from 100Hz to 100kHz—as well as line/load regulation of <1mV static, <10mV transient, and power supply rejection of less than 70dB at 1kHz. The integrated step-down DC/DC converter requires no external Schottky diode yet provides up to 95 per cent efficiency throughout the whole operating range. The DC/DC converter's 2.2MHz switching frequency saves PCB space by enabling the use of a tiny, low-profile inductor. In addition, a 60mA 5V charge pump together with five programmable current sinks is included to supply LEDs for backlighting the display. The on-chip low-distortion audio power amplifier provides 1W at 8Ω for speaker-phone operation, Hi-Fi ringtones or other audio uses.

The AS3605 Micro PMIC also features a battery charger for Li-Ion batteries, including the charging algorithms for automatic trickle charging, programmable constant voltage and constant current charging.

Processor and memory power supplies must follow precise start-up sequences to prevent serious damage. Therefore it is critical that the voltages are switched on and off in the correct order. Compared to a discrete solution consisting of a collection of stand-alone DC/DC converters, LDOs and chargers, the task is greatly simplified with the AS3605. With its software-programmable start-up sequences, the AS3605 brings new flexibility to the market for Micro PMICs. Other competitors offer PMICs with fixed start-up sequences that must be selected with external resistors.

The AS3605's output voltage and the timing of all regulators are programmed via software. With the software and demo board, the AS3605's OTP memory can be easily programmed, enabling fast prototype runs for quick market introduction. The slope of the ramp can be set for the step-down converters. The user can program the start-up sequence with timing steps of 1ms or 4ms. In order to control other parts of the system, the general purpose I/O pins can be programmed to a specific timing.

The AS3605 is controlled via a serial interface and integrates all necessary system specific functions such as Reset, Watchdog, and Power-On Detection. Output voltages and start-up timings can be programmed via the internal OTP memory.

Housed in a 40-pin 5x5mm QFN package, the AS3605 Micro Power Management Unit is specified for operation from a battery supply range of 3V–5.5V over an ambient temperature range of -40°C to 85°C.

The AS3605 Micro PMIC is available now.

Comment on "Micro PMIC designed for Li-Ion power..."
*  You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.


Go to top             Connect on Facebook      Follow us on Twitter      Follow us on Orkut

Back to Top