FSAU3157P6X

Analog Switches, Multiplexers, Demultiplexers Overview

The FSAU3157P6X is a single-pole double-throw (SPDT) analog switch or 2:1 multiplexer/de-multiplexer bus switch manufactured by onsemi. It operates within a supply voltage range of 1.65V to 5.5V and features an on-resistance maximum of 15Ω at VCC=4.5V with IO=-30mA. The device supports rail-to-rail signal handling and includes break-before-make circuitry to prevent signal disruption during switching. Key electrical parameters include a quiescent supply current of 1µA, a -3dB bandwidth of 250MHz, and propagation delay ranging from 0.8ns to 5.2ns depending on voltage. It is housed in a 6-lead SC70 surface-mount package.

Analog Switches, Multiplexers, Demultiplexers Feature Summary

• Integrated Undershoot Hardened Circuit (UHC) prevents unintended switch activation during input undershoot events.
• Break-before-make select circuitry ensures the B port remains connected to A without temporary overlap during control transitions.
• Control input tolerates voltages up to 7.0V independent of the VCC operating range.

Analog Switches, Multiplexers, Demultiplexers Applications

• Analog and digital signal routing
• Multiplexer and de-multiplexer bus switching
• Portable instrumentation

Analog Switches, Multiplexers, Demultiplexers Procurement Notes

Verify component authenticity through authorized distributors or official manufacturer channels. Confirm RoHS compliance status and check for obsolescence notices, as legacy Fairchild Semiconductor products may have limited availability or end-of-life status. Ensure packaging specifications match design requirements.

Analog Switches, Multiplexers, Demultiplexers Selection Notes

Select this component when low-voltage operation between 1.65V and 5.5V is required alongside high-speed signal integrity. The 250MHz bandwidth and low charge injection make it suitable for applications demanding minimal signal distortion. Verify that the 15Ω maximum on-resistance meets the specific load current requirements of the target circuit.

Analog Switches, Multiplexers, Demultiplexers Part Context

This part belongs to the NC7SBU3157/FSAU3157 family of low-voltage SPDT analog switches originally developed by Fairchild Semiconductor. The FSAU3157P6X designation specifically refers to the version packaged in a 6-lead SC70 format with tape and reel packing. It shares functional characteristics with the NC7SBU3157 variant but carries distinct manufacturer branding.

Analog Switches, Multiplexers, Demultiplexers Replacement Considerations

NC7SBU3157P6X is a functionally equivalent part within the same datasheet specification.

Analog Switches, Multiplexers, Demultiplexers FAQ

What is the purpose of the UHC feature?

The Undershoot Hardened Circuit (UHC) senses undershoot at the I/Os and prevents voltage differentials from developing, thereby stopping the switch from turning on unintentionally during transient voltage events.

How does the break-before-make circuitry function?

It prevents disruption of signals on the B port by ensuring both switches are not temporarily enabled simultaneously during select pin switching.

What is the maximum voltage tolerance for the control input?

The control input can tolerate voltages up to 7.0V, which is independent of the VCC operating range.