ADG438FBN

Analog Switches, Multiplexers, Demultiplexers Overview

The ADG438FBN is a high-performance, fault-protected analog multiplexer featuring eight single channels. It utilizes a series n-channel, p-channel, and n-channel MOSFET structure to provide device and signal source protection against overvoltages ranging from −40 V to +55 V. The device supports dual supply operation with an on-resistance of 270 Ω typically at ±15 V. It offers fast switching times with a maximum tON of 250 ns and tOFF of 150 ns, ensuring break-before-make construction to prevent momentary shorting.

Analog Switches, Multiplexers, Demultiplexers Feature Summary

• Fault protection withstands continuous overvoltage inputs from −40 V to +55 V
• Break-before-make switching prevents momentary shorting of input signals
• Trench isolation eliminates latch-up between p-channel and n-channel MOSFETs
• All switches turn off when power supplies are removed

Analog Switches, Multiplexers, Demultiplexers Applications

• Data acquisition systems
• Industrial and process control systems
• Avionics test equipment
• Signal routing between systems
• High reliability control systems

Analog Switches, Multiplexers, Demultiplexers Procurement Notes

Verify the ordering suffix 'BN' corresponds to the 16-Lead Plastic Dual In-Line Package (N-16) as specified in the official Analog Devices ordering guide. Confirm that the component meets the required temperature range of −40°C to +125°C. Ensure design compatibility with TTL- and CMOS-compatible logic inputs for address selection and enable functions.

Analog Switches, Multiplexers, Demultiplexers Selection Notes

Select this component for applications requiring robust fault protection against extreme overvoltages while power supplies are active or absent. The eight-channel configuration is suitable for multiplexing multiple sensor lines. Consider the 270 Ω typical on-resistance and 93 dB off-isolation for signal integrity requirements. Verify that the 16-pin DIP package fits the target PCB layout constraints.

Analog Switches, Multiplexers, Demultiplexers Part Context

The ADG438FBN belongs to the ADG438F/ADG439F family of CMOS analog multiplexers manufactured by Analog Devices. This family is designed for high-reliability environments where signal source protection is critical. The ADG438F variant specifically provides eight single-ended channels, distinguishing it from the differential channel configuration of the ADG439F.

Analog Switches, Multiplexers, Demultiplexers Replacement Considerations

Public confirmed substitutes include other Analog Devices fault-protected multiplexers such as the ADG439F for differential applications. When replacing, ensure the substitute maintains the same −40 V to +55 V overvoltage tolerance and compatible pinout if form-factor retention is required.

Analog Switches, Multiplexers, Demultiplexers FAQ

How does the ADG438F protect signal sources during power loss?

When power supplies are off, all channels switch off, appearing as an open circuit with only nanoamperes of leakage current, thereby protecting both the multiplexer and the connected signal sources.

What is the purpose of the break-before-make construction?

It guarantees that the previous channel disconnects before the new channel connects, preventing momentary shorting of input signals during switching transitions.

Can the device handle overvoltages when powered down?

Yes, the device can withstand continuous overvoltage inputs from −40 V to +55 V regardless of whether the power supplies are present or not.