SCDA047 January   2024 TMUX1108 , TMUX1119 , TMUX121 , TMUX136 , TMUX1574

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Parameters Affected when Cascading Multiplexers
  6. 3Summary
  7. 4References

Summary

Using multiple multiplexers in series (cascading) allows for flexibility and versatility to create unique designs but also requires extra parametric checks before finalizing a design. Selecting a lower leakage multiplexer is an important factor in high precision applications as the leakage adds linearly. A low On-Resistance multiplexer is more desirable in applications with a lower load, such a 50-ohm coax load, to help reduce the insertion loss per multiplexer. The overall bandwidth of the system must always be evaluated as the bandwidth decays as more cascading stages are added. The loss is greatest in the first stage, where the bandwidth was reduced by nearly half. In most cascaded multiplexer applications, we recommend to do a bench level analysis of the cascaded networks compatibility with the specific system as use cases, system requirements and environments vary.

Table 3-1 Recommended Devices to Use When Cascading Mutliplexers
Hero Devices
Applications
Device Channel and Configuration High Speed Low Leakage Precision Small Load High Voltage
TMUX136 2ch SPDT (2:1) 6GHz Bandwidth 2Ω On-Resistance
TMUX1574 4ch SPDT (2:1) 2GHz Bandwidth 2Ω On-Resistance
TMUX1108 1ch 8:1 3pA On-Leakage 2.5Ω On-Resistance
TMUX121 2ch SPDT (2:1) 3GHz Bandwidth 3Ω On-Resistance
TMUX7612 4ch SPST (1:1) 3.7pA On-Leakage 1.35Ω On-Resistance 50V