ZHCSHR4F January 2009 – April 2018 DAC7568 , DAC8168 , DAC8568
PRODUCTION DATA.
The DAC7568, DAC8168, and DAC8568 are designed for single-supply operation, but a bipolar output range is also possible using the circuit in either Figure 128 or Figure 129. The circuit shown gives an output voltage range of ±VREF. Rail-to-rail operation at the amplifier output is achievable using an OPA703 as the output amplifier.
The output voltage for any input code can be calculated with Equation 4:
Where:
DIN = decimal equivalent of the binary code that is loaded to the DAC register. It can range from 0 to 4095 for DAC7568 (12 bit), 0 to 16,383 for DAC8168 (14 bit), and 0 to 65535 for DAC8568 (16 bit).
n = resolution in bits; either 12 (DAC7568), 14 (DAC8168) or 16 (DAC8568)
Gain = 1 for A/B grades or 2 for C/D grades.
With VREFIN/VREFOUT = 5V, R1 = R2 = 10kΩ, for grades A and B.
This result has an output voltage range of ±5V with 0000h corresponding to a –5V output and FFFFh corresponding to a +5V output for the 16-bit DAC8568, as shown in Figure 128. Similarly, using the internal reference, a ±2.5V output voltage range can be achieved, as Figure 129 shows.