Analog Devices Inc./Maxim Integrated MAX4690EWE

Summary of MAX4690EWE Analog Switch Features

The MAX4690EWE, developed by Analog Devices Inc./Maxim Integrated, represents a dual single-pole, single-throw (SPST) CMOS analog switch solution, configured for normally open operation. Integrating key design features, the MAX4690EWE offers engineers low on-resistance, fast switching times, and robust signal-handling capabilities, making it ideal for modern automatic test equipment, data acquisition systems, and relay replacement scenarios. Housed in a space-efficient 16-SOIC surface-mount package, this device targets demanding applications where precise analog switching and low power dissipation are critical.

Main Electrical Parameters and Performance of MAX4690EWE

Engineers evaluating the MAX4690EWE will note several standout specifications:

On-State Resistance: The MAX4690EWE achieves a low on-resistance of 1.25Ω maximum for each switch, ensuring minimal signal loss and high fidelity.

Channel Matching and Flatness: Channel-to-channel resistance matching (∆Ron) is guaranteed to within 0.3Ω, with on-resistance flatness also specified at 0.3Ω max across the signal range, supporting consistent performance over varying input levels.

Signal Range and Rail-to-Rail Handling: Each analog switch is designed for rail-to-rail signal capability, supporting the full input excursion from supply rails.

Leakage Performance: Off-leakage currents are tested to be as low as 5nA at +85°C—ideal for high-impedance signal paths requiring ultra-low leakage.

Switching Dynamics: Fast turn-on and turn-off times are specified at 275ns and 175ns respectively, accommodating rapid, precise signal routing.

Bandwidth and Isolation: With a -3dB bandwidth of 550pC charge injection, and robust crosstalk isolation at -65dB @ 1MHz, the device maintains integrity in mixed analog-digital environments.

Supply Voltage Versatility: The device supports both single (+4.5V to +36V) and dual (±4.5V to ±20V) supply configurations, with separate logic voltage input ensuring TTL/CMOS compatibility across supply ranges.

Packaging, Installation, and Environmental Factors for MAX4690EWE

The MAX4690EWE is available in a standard 16-lead SOIC (0.295", 7.50mm width), optimized for surface-mount assembly and high-density board layouts. Rated for operating temperatures between -40°C and +85°C, it satisfies the requirements for industrial and communications-grade environments. While the device is RoHS non-compliant, its Moisture Sensitivity Level (MSL) is rated at 1 (Unlimited), supporting reflow soldering and extended manufacturing cycles. The package and its lead spacing are suited to automated placement and inspection.

Operational Features and Application Guidance for MAX4690EWE

At the heart of the MAX4690EWE are its two independent SPST analog switches, each controlled via TTL/CMOS-compatible logic inputs. In real-world engineering, the rail-to-rail signal handling allows designers to route analog signals up to the full supply voltage without distortion, supporting applications like sample-and-hold circuits, PBX/PABX systems, and communication system signal routing.

The CMOS construction replaces bulky reed relays, offering lower power, improved reliability, and reduced board footprint. The device’s channel matching and low leakage enable its use in multiplexer/demultiplexer topologies for data acquisition, ensuring signal accuracy when switching sensitive analog signals. The robust ESD protection (>2kV per Method 3015.7) further supports deployment in noisy or industrial environments.

Pinout Details and Signal Logic of MAX4690EWE

Pinout details for the MAX4690EWE are critical for design integration:

Logic control inputs (IN1, IN2) determine the ON/OFF state of each SPST analog switch.

The analog signal path is defined by the COM1/NO1 and COM2/NO2 terminals, with both NO switches connecting on logic high.

Supply pins include V+ (positive analog supply), V(negative analog supply—connected to GND for single supply), and VL (logic voltage).

Pins not internally connected (N.C.) should be tied to GND or a low-impedance node for optimal isolation.

The SOIC package arrangement supports straightforward routing in both dual and single supply systems, facilitating simple drop-in upgrades or replacements.

Design Notes and Power Safeguards for MAX4690EWE

CMOS analog switches, such as the MAX4690EWE, require careful attention to supply sequencing and overvoltage protection to maximize longevity and reliability. The recommended power-up sequence is V+ first, followed by V-, then logic and signal inputs. If strict supply sequencing is not feasible, the addition of small-signal diodes in series with supply pins and a Schottky diode between V+ and VL provides robust overvoltage protection without compromising switch resistance or leakage. Care must also be taken to ensure that input signals do not exceed supply rails, as internal protection diodes clamp excess voltages, and maximum ratings must not be exceeded to avoid permanent damage.

Comparable Alternatives and Replacement Options for MAX4690EWE

For engineers faced with supply constraints or required to identify alternatives due to obsolescence, considering equivalent or replacement models is essential. The MAX4690EWE belongs to a family of analog switches including MAX4680 (dual NC switch configuration) and MAX4700 (one NC and one NO switch), also by Analog Devices Inc./Maxim Integrated. These share common electrical footprints and similar operating characteristics but differ in switching logic architecture. Competitor devices with similar low on-resistance, dual SPST configuration, and rail-to-rail operation may serve as direct substitutes—engineers should review parameters such as channel matching, off-leakage performance, switching times, and package compatibility to ensure seamless integration.

Conclusion

The MAX4690EWE dual SPST CMOS analog switch delivers a powerful combination of low on-resistance, fast switching, rail-to-rail signal handling, and versatile supply voltage options in a compact, industrially-rated package. Its channel matching performance, leakage control, and ESD protection make it an excellent choice for high-fidelity analog routing across a range of demanding engineering applications. When evaluating devices for data acquisition, relay replacement, or test and measurement equipment, the MAX4690EWE and its related family offer selection engineers a robust and reliable solution that is straightforward to integrate into new or existing board designs. As device availability changes or compliance requirements evolve, engineers should consider both in-family switches and parameter-matched competitive offerings to meet technical and supply chain objectives.