Configurable applications processor tackles multiple mobile environments
Dialog Semiconductor's DA9052 is the first fully configurable, programmable-platform PMIC to become available. Its 7 x 7mm package provides up to 14 individual power supplies that comprise four dc/dc buck converters—providing 0.5 to 3.6V at up to 1A—and 10 programmable LDOs. Sixteen general-purpose I/Os are available to support system wake-up and peripheral control. The chip interfaces directly with a lithium-ion or lithium-polymer battery pack and features precise current/voltage charging powered from self negotiating USB or dc wall plug supply.
To cater for the most popular peripherals and user interfaces, the chip also integrates a white LED driver circuit that suits display backlighting, an ADC for system measurements, and a touchscreen controller. Two serial control interfaces enable communications with all common processor families—see figure 1:
Fig 1: The DA9052 integrates 4 dc/dc converters, 10 LDOS, and system monitoring and control functions.
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A device with this complement of resources can become quite challenging to configure. Accordingly, an evaluation board is available to simplify development, complete with an onboard USB-to-I2C bridge that enables connection to a PC. Supporting all major ARM-based processor families, the graphical user interface within the Windows-compatible Power Commander configuration and programming utility presents a view of the PMIC's resources that permits easy and logically-organised access to configure the hardware.
On start-up, the software displays a configuration panel that allows you to select a predefined template for the target processor family from a pull-down menu, make modifications, and store the result as a new project—see figure 2:
Fig 2: The Power Commander Configuration Panel.
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Clicking on the button of each LDO regulator opens its configuration panel, allowing you to assign it a name, select whether it will be enabled immediately or under power sequence control, and define its start-up voltage and any timing details.
Configuring the buck converters works in the same way. Additionally, you can set internal current limits and modify the converters' switching behaviour. For instance, it's possible to select constant frequency PWM operation when the wireless peripherals are active, but otherwise use comparatively noisy pulse skipping mode switching that offers greater efficiency, especially at light loads. Similarly, you can name each GPIO, configure it as an input or output, and define any applicable conditions. Clicking on the Power Sequence button then reveals a drag-&-drop timing screen, where you can define power-up and power-down sequences. This window mimics a processor's timing diagram specification—see figure 3:
Fig 3: An intuitive drag-&-drop interface configures power sequencing.
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To minimise production costs, the final PMIC is produced as a one-time-programmable (OTP) device. The configuration process is thus responsible for generating the conditions that will be permanently programmed into the production PMIC to create a configuration that's precisely tailored to the target processor and its peripherals.
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