Datasheet

SLDU010
TI CONFIDENTIAL – NDA Restrictions
Page 11 of 50
Figure 6. Channel 1 Resistive Bridge Sensor Simulator
3.1.2 Buffered DAC Outputs
The second way to excite the voltage inputs to the PGA400-Q1 is to use the buffered DAC
outputs on the EVM. The DAC8574, a four-channel 16-bit DAC, is used to generate voltage
signals that can be used to excite the VIN1P/VIN1N and VIN2P/VIN2N inputs. When the DAC
MUX is set to the VIN1P/VIN1N and VIN2P/VIN2N sensor inputs, the DAC buffers over-drive the
voltage that the resistive bridge was previously producing. The buffered DAC voltage is
measured with the ADS1100, 16-bit ADCs, and then adjusted to servo out errors. The DACs are
controlled with the GUI which will be described later in this guide. The figure below shows the
DACs and the DAC buffers.