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The chip
Inside the chip [click for enlarging]
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National Semiconductor announced a digitally-controlled PowerWise energy management unit (EMU), that reduces the power consumption of digital processors used in battery-powered handheld products. The LP5550 EMU, used in conjunction with National’s advanced power controller (APC) and intelligent energy manager (IEM) technology from ARM, reduces the power consumption of digital processor cores by up to 70 percent. The device and APC also support the PowerWise Interface (PWI) open-industry standard introduced by National Semiconductor and ARM.
The LP5550 supports the PWI interface, a 2-pin, high-speed serial power management control interface for advanced processor power management. To enable adaptive voltage scaling, the device includes a digitally-controlled, 300 mA, 0.6V to 1.2V buck regulator with up to 90 percent efficiency. In addition, it has three programmable low drop-out (LDO) regulators with output voltages ranging from 0.6 V to 3.3V. One LDO supports 100 mA and the other two support 250 mA. Packaged in a lead-free, 16-pin LLP package, the LP5550 operates over the full temperature range from –40 degrees C to +85 degrees C, with input voltages from 3.0V to 5.5V. The LP5550 is available now and is priced at $4.50 in 1,000-unit quantities. Lead-free package options are also available.
Advanced Power Controller
Compliant with the AMBA specification, National’s APC is a synthesizable macro-cell that includes a hardware performance monitor. The APC automatically calibrates for process and temperature variations, and communicates with the LP5550 using the PWI interface. The processor supply voltages are reduced to the absolute minimum necessary to meet the required level of performance at all operating frequencies. The APC is available for licensing from ARM.
Adaptive Voltage Scaling
Adaptive voltage scaling is a technique for determining the minimum supply voltage for a digital processor during operation. This technology reduces the supply voltage of a digital processor by removing voltage margins associated with process, temperature, IR-drop and regulator tolerances. The advanced power controller, together with National’s LP5550, enables customers to easily deploy this technology in their platforms.
