AnalogicTech’s New PMICs Extend Battery Life by Delivering Low Noise Power at High Efficiency
(Product News, 05 Sep 2008 )
Advanced Analogic Technologies, a developer of power management integrated circuits for communications, computing and consumer electronic devices, announced the AAT2782 and AAT2783, two new power management ICs (PMICs) for portable applications. Combining two step-down converters with a low VIN LDO, these new devices can be used to power both traditional power management functions and noise-sensitive circuits without compromising power efficiency.
Efficient Power Conversion The AAT2782 and AAT2783 operate off a 2.7V to 5.5V input range and provide three independently regulated DC outputs: two step-down converters and one low input voltage LDO. The two step-down converters on the AAT2782 deliver 1200 mA and 600 mA respectively. On the AAT2783 the two step-down converters supply 1000 mA and 400 mA. On each IC both converters use current mode control to ensure fast transient response and stable operation across the entire operating range. A 1.3 MHz switching frequency supports the use of small external filters.
The low input voltage LDO on both devices is optimized for low noise operation. Designed to operate off a 1.7V input, the LDO delivers up to 400 mA with a -80 dB power supply rejection ratio (PSRR) and 65 µVRMS output noise with an optional bypass capacitor. The LDO’s output voltage is factory set at 1.2V.
The step-down converters on both devices offer high efficiency rates. Using the LDO to post-regulate the output of the second step-down converter for low-noise operation, both devices achieve efficiency levels up to 80 percent.
The two new PMICs are fabricated in AnalogicTech’s proprietary Modular BCD process. Total quiescent current is 170 µA for the AAT2782 and 135 µA for the AAT2783. Both devices feature 200 µs internal soft start and over-temperature protection.
Modular BCD Process Technology The AAT2782 and the AAT2783 are fabricated in AnalogicTech’s proprietary ModularBCD process. Compared to linear-IC legacy fabs and generic digital CMOS foundries, ModularBCD provides more cost-effective, modular fabrication of analog, power and mixed-signal ICs by monolithically integrating fully-isolated CMOS at multiple voltages, complementary bipolar transistors, and robust power devices. This process avoids complex and expensive techniques such as epitaxy and high-temperature diffusion. Devices manufactured in ModularBCD offer higher efficiency, smaller size and higher levels of integration than those fabricated in many other processes.