MCP4728 Quad Channel 12-bit Digital-to-Analog Converter
MCP4728 is a quad-channel, 12-bit voltage output Digital-to-Analog Converter (DAC) with non-volatile memory and I²C compatible serial interface. You can program the DAC input codes, device configuration bits, and I²C address bits to the non-volatile memory (EEPROM) by using I²C compatible interface commands. The non-volatile 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.
Features
- 12-bit Resolution
- Four Buffered Voltage Outputs
- Single-Supply Operation: 2.7 V to 5.5 V
- On-Board Non-Volatile Memory (EEPROM)
- Normal or Power-Down Mode
- Internal or External Voltage Reference Selection
- Rail-to-Rail Output
- Low-Power Consumption
- ±0.2 LSB DNL (typical)
- I²C Interface
- Address Bits: User Programmable to EEPROM
- Standard (100 kbps), Fast (400 kbps), and High Speed (3.4 Mbps) Modes
- 10-lead Micro Small Outline Package (MSOP)
- Extended Temperature Range: -40 °C to +125 °C
Target Applications
- Set Point or Offset Adjustment
- Sensor Calibration
- Closed-Loop Servo Control
- Low-Power Portable Instrumentation
- PC Peripherals
- Programmable Voltage and Current Source
- Industrial Process Control
- Instrumentation
- Bias Voltage Adjustment for Power Amplifiers
Reference Materials
- Microchip Direct Product Search: MCP4728
- MCP4728 DAC
- MCP6544 Push-pull, Quad Comparator
- Voltage Divider
Application: Setting the DC Set Point for Sensor Circuit
A common DAC application is digitally controlling the set point and/or calibration of parameters in a signal chain. Figure 1 illustrates controlling the Direct Current (DC) set point of a light detector sensor using the MCP4728 12-bit quad DAC and MCP6544 comparator. The DAC provides 4,096 output steps. If G = 1 and internal reference voltage options are selected, then the internal 2.048 V reference (Vref) would allow 500 μV of resolution. If G = 2 is selected, the internal 2.048 Vref would allow 1 mV of resolution. If a smaller output step size is desired, the output range would need to be reduced. Using a gain of one is a better choice than using a gain of two as a configuration option for a smaller step size. Using a voltage divider at the DAC output is another method for obtaining a smaller step size.
