MAX394: High-Speed, Low-Voltage, Quad Analog Switch IC

The MAX394 is a high-speed, low-voltage, quad, single-pole/single-throw (SPST) analog switch designed by Maxim Integrated (now part of Analog Devices). Known for its low on-resistance, high bandwidth, and low power consumption, it’s widely used in data acquisition, signal routing, and measurement systems.

✅ Key Features

Quad SPST configuration – Four independent single-pole/single-throw switches in one IC.
Low ON resistance – Typically around 35 Ω for efficient signal transfer.
Wide supply range – Operates from ±3 V to ±8 V dual supply or +3 V to +16 V single supply.
Low leakage currents – Ideal for precision applications.
Fast switching time – tON ≈ 150 ns, tOFF ≈ 120 ns.
Low charge injection – Improves accuracy in analog signal routing.
TTL/CMOS logic compatible – Works easily with microcontrollers and digital logic.
Wide bandwidth – Suitable for high-speed analog applications.
Package options – Available in 16-pin DIP, SOIC, and TSSOP.

Specifications (Typical Values)

Parameter
Value
Configuration
Quad SPST Analog Switch
Supply Voltage Range (Single)
+3 V to +16 V
Supply Voltage Range (Dual)
±3 V to ±8 V
ON Resistance (RON)
~35 Ω
ON Resistance Match
±3 Ω
Leakage Current (IOFF)
< 1 nA
Switching Time
tON ≈ 150 ns, tOFF ≈ 120 ns
Logic Input Compatibility
TTL/CMOS
Operating Temperature
–40 °C to +85 °C
Package
16-pin DIP, SOIC, TSSOP

Common Applications

Data acquisition systems – Routing analog signals to ADCs or measurement devices.
Audio signal switching – Selecting between multiple inputs or outputs.
Video signal routing – Low distortion makes it suitable for composite video.
Test and measurement equipment – Automated test setups for switching channels.
Industrial instrumentation – Precise analog signal control in harsh environments.
Communication systems – RF and IF signal selection in radios and transceivers.

Functional Overview

The MAX394 integrates four independent SPST analog switches that can conduct both analog and digital signals. With its low leakage and fast switching speed, it’s suitable for precision measurement systems. The low ON resistance ensures minimal signal attenuation, and the TTL/CMOS-compatible control inputs make it easy to interface with microcontrollers or FPGA logic.

Advantages

Compact Design – Four switches in a single package reduce PCB space.
Versatile Operation – Works with both single and dual supply systems.
High Precision – Low leakage and charge injection maintain signal integrity.
High Speed – Suitable for high-frequency analog signals

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