MAX4891ETJ+

Analog Switches - Special Purpose Overview

The MAX4891ETJ+ is a high-speed analog switch designed for 10/100/1000 Base-T Ethernet applications. It features four bidirectional SPDT channels and one built-in LED switch, housed in a 32-pin TQFN-EP package. The device operates on a single +3.0V to +3.6V supply with a maximum quiescent current of 450µA. Key electrical parameters include a typical on-resistance (RON) of 4Ω and maximum of 6.5Ω, an ultra-low on-capacitance (CON) of 6.5pF, and a -3dB bandwidth of 1GHz. It supports turn-on times up to 50ns and turn-off times up to 40ns, functioning reliably within the -40°C to +85°C temperature range.

Analog Switches - Special Purpose Feature Summary

• Integrates four bidirectional multiplexer/demultiplexer channels alongside one dedicated LED switch for docking station indicator routing.
• Utilizes an internal two-stage charge pump to maintain consistently low on-resistance across the full input signal range.
• Features optimized pin-out configurations that facilitate direct interfacing with Ethernet transformers and PHYs.
• Incorporates internal flyback capacitors to minimize external component requirements, reducing board space and design complexity.

Analog Switches - Special Purpose Applications

• Notebooks and docking stations requiring Ethernet interface switching
• Servers and routers with Ethernet interfaces needing signal routing
• Board-level redundancy protection for line cards
• SONET/SDH signal routing systems

Analog Switches - Special Purpose Procurement Notes

Verify the specific ordering suffix against official manufacturer documentation to confirm package type and lead-free status. Ensure compatibility with the required operating voltage range and environmental specifications before procurement. Cross-reference the part number with authorized distributors to confirm availability and authenticity.

Analog Switches - Special Purpose Selection Notes

Select the MAX4891ETJ+ when a single integrated LED switch is required alongside four Ethernet signal paths. Compare against the MAX4890 if no LED switching is needed, or the MAX4892 if three LED switches are necessary. Confirm that the 32-pin TQFN package footprint aligns with the target PCB layout constraints.

Analog Switches - Special Purpose Part Context

The MAX4891 belongs to the MAX4890/MAX4891/MAX4892 family of high-speed analog switches from Analog Devices/Maxim Integrated. This series targets 10/100/1000 Base-T applications, offering low capacitance and on-resistance to meet Ethernet insertion and return-loss specifications while simplifying docking station designs.

Analog Switches - Special Purpose Replacement Considerations

Public confirmed substitutes include the MAX4890ETJ+ and MAX4892ETX+. Verify functional differences regarding the number of integrated LED switches and package pin counts before substitution.