188.8.131.52 Detailed Design Procedure
The simple design of Figure 88 has several options and details to consider, which include:
- For split-supply operation, the disable control line must operate to within 0.55 V of the negative supply to disable a channel. A logic level shift is required.
- Any combination of gains can be implemented. However, the signal bandwidths may vary widely through the gain bandwidth product effect between the two channels if the gains are widely separated. If a more constant bandwidth between gains is desired, consider adding a fixed RC filter after the combined outputs at a lower cutoff frequency than the slowest gain setting.
The TIDA-01565 Wired OR MUX and PGA Reference Design demonstrates the use of the OPAx837 in wired-OR multiplexer and programmable gain amplifier applications.