AN-1246: Software Configurable 16-Bit Quad Channel Unipolar/Bipolar Voltage Output Using the AD5754 DAC
Circuit Function And Benefits
This circuit provides, unipolar and bipolar data conversion using the AD5754BREZ, a quad, 16-bit, serial input, unipolar/bipolar voltage output DAC, and the REF192ESZ precision 2.5 V voltage reference. The only additional external components needed for this 16-bit DAC circuit are decoupling capacitors on the supply pins and reference input, leading to savings in cost and board space. This circuit is well suited for closed-loop servo control applications.
Circuit Description
| Product | Description |
| AD5754 | Complete quad, 16-bit, unipolar/bipolar voltage output DAC |
| REF192 | Precision 2.5 V voltage reference |
The AD5754 is a digital-to-analog converter that offers guaranteed 16-bit monotonicity, integral nonlinearity (INL) of ±16 LSB, 0.1% total unadjusted error (TUE), and 10 μs settling time. The AD5754 also integrates reference buffers and output amplifiers, which leads to further savings in both cost and board space. Performance is guaranteed over the following supply voltage ranges: AVDD supply range from +4.5 V to +16.5 V and AVSS supply range from −4.5 V to −16.5 V. AVSS can be connected to 0 V if only unipolar outputs are required. The output range can be individually programmed for each of the four channels. The options are 0 V to +5 V, 0 V to +10 V, 0 V to +10.8 V, −5 V to +5 V, −10 V to +10 V, and −10.8 V to +10.8 V. The input coding is user selectable twos complement or offset binary for a bipolar output (depending on the state of the BIN/2sCOMP pin). Coding is straight binary for a unipolar output. Figure 2 shows that the typical output error of this circuit at 25°C ambient temperature is less than 0.06 %FSR.
Figure 1. Unipolar/Bipolar Configuration of the AD5754 DAC (Simplified Schematic).
Figure 2. Voltage Output Error.
The circuit must be constructed on a multilayer PC board with a large area ground plane. Proper layout, grounding, and decoupling techniques must be used to achieve optimum performance (see MT-031 Tutorial and MT-101 Tutorial).
参考資料
Kester, Walt. 2005. The Data Conversion Handbook, Chapter 3 and Chapter 7. Analog Devices.
MT-015 Tutorial, Basic DAC Architectures II: Binary DACs. Analog Devices.
MT-031 Tutorial, Grounding Data Converters and Solving the Mystery of AGND and DGND. Analog Devices.