Integrated Power Controller Manages Multiple Power Domains

Oct 5, 2005 12:51 PM

Dialog Semiconductor Plc has launched a general-purpose device for use as a core building block in power management subsystems in portable electronics equipment, audio players, cellular handsets and digital cameras. The new DA9025 high-performance power management controller takes a system level approach to managing the multiple power domains and voltage requirements of lithium-powered portable applications, integrating a number of functions and interfacing directly with a battery pack. Typical handheld applications for the DA9025 include those with a lithium power source.

The new IC contains four low-power, high-performance, low dropout regulators based on Dialog Semiconductor's unique “Smart Mirror” technology, a real-time clock supply and a high-efficiency buck converter. The key advantage of this approach is that it reduces the cost and PCB overhead of having to build in multiple off-the-shelf, low-integration power management components from multiple vendors. The DA9025 can be used either standalone with pre-determined power-up sequence for simple operation, or controlled by an I²C bus for greater control and programmability of output voltages and power in individual blocks. Power efficiency and thus longer battery life is enabled using Dialog Semiconductor's patented Smart Mirror architecture—a technology that optimizes quiescent current consumption by matching it to the current demand and performance required, removing the need for a low power mode and the associated hardware and software overhead.

The DA9025's low dropout voltage regulators are designed for supplying stable voltages to various parts of the system. The low dropout linear regulators are optimized for critical system parameters such as low noise, high power supply rejection or low quiescent current. Two of the LDOs may be used to supply audio or RF circuits as they are low noise and typically exhibit more than 80-dB power supply rejection. Under I²C control, the regulator output voltage also is programmable. Battery supplies to the regulators are separated to maximize isolation.

A fifth integrated regulator provides a supply for a real-time clock. This is permanently active when the battery is connected but is a very low quiescent current design. The integrated dc-dc buck converter has a programmable range of 0.85 V to 3.3 V, with a default supply of 1.8 V at up to 400 mA. In many systems, the buck converter is used to power the system processor and memory. The buck converter may be set to operate in either synchronous or asynchronous modes to optimize operating efficiency depending on load current. The converter has integrated switching FETs and requires a minimum number of external components. Under I²C control, the buck converter output voltage also is programmable, allowing very low voltage processors to be used. The DA9025 is available now in a 4-mm × 4-mm 24 QFN package.

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