Microchip Technology has announced a quad 12-bit DAC that remembers its settings in an internal EEPROM. The MCP4728 has a ±2%, 2.048V voltage reference, but you can also an external reference. The reference has a 1.2 μV/= noise floor with a 400-Hz flicker-noise corner. You communicate with the part over an I2C (inter-integrated-circuit) bus in standard 100-kbps, fast 400-kbps, and high-speed 3.4-Mbps modes. You can individually shut down each DAC; total shutdown current is 0.04 μA. You can set the outputs to go to a low, medium, or high impedance state during shutdown. Operating current is 800 μA. The devices features rail-to-rail outputs over the 2.7 to 5.5V power-supply range. Typical DNL (differential nonlinearity) is ±0.2 LSBs with a maximum of ±0.75 LSBs, which ensures that the device remains monotonic across all input codes. The DAC contains a power-on circuit for predictable operation.
The device has applications in consumer products, such as personal media players, digital cameras, and GPS (global-positioning-system) devices. Medical applications include portable glucose meters, blood pressure, and heart-rate monitors. It also finds use in industrial products, such as handheld instruments, motor-control applications, and temperature and light control. The unit’s wide temperature range also makes it suitable for automotive applications.
Microchip TechnologyClick here for the illustrations:
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CaptionFig 1: The MCP4728EV evaluation board interfaces with the PICkit serial analyzer, which converts your computer’s USB to I2C SMBus, SPI, or USART protocols. You can also use your own I2C interface board.
Fig 2: You control the microchip MCP4728 quad DAC with the I2C bus. The device’s non-volatile memory allows it to power up without microprocessor supervision.
