12位四路数字模拟转换器与EEPROM存储器MCP4728

　　The MCP4728 device is a quad， 12-bit voltage output Digital-to-Analog Convertor （DAC） with nonvolatile memory （EEPROM）。 Its on-board precision output amplifier allows it to achieve rail-to-rail analog output swing. The DAC input codes， device configuration bits， and I 2C address bits are programmable to the nonvolatile memory （EEPROM） by using I2C serial interface commands. The nonvolatile memory feature enables the DAC device to hold the DAC input codes during power-off time， allowing the DAC outputs to be available immediately after power-up with the saved settings. This feature is very useful when the DAC device is used as a supporting device for other devices in the application’s network. The MCP4728 device has a high precision internal voltage reference （VREF = 2.048V）。 The user can select the internal reference or external reference （VDD） for each channel individually. Each channel can be operated in Normal mode or Power-Down mode individually by setting the configuration register bits. In Power-Down mode， most of the internal circuits in the powered down channel are turned off for power savings， and the output amplifier can be configured to present a known low， medium， or high resistance output load. The MCP4728 device includes a Power-on Reset （POR） circuit to ensure reliable power-up and an on-board charge pump for the EEPROM programming voltage. The MCP4728 has a two-wire I2C compatible serial interface for standard （100 kHz）， fast （400 kHz）， or high speed （3.4 MHz） mode. The MCP4728 DAC is an ideal device for applications requiring design simplicity with high precision， and for applications requiring the DAC device settings to be saved during power-off time. The MCP4728 device is available in a 10-lead MSOP package and operates from a single 2.7V to 5.5V supply voltage.