The MAX4890/MAX4891/MAX4892 high-speed analog switches meet the needs of 10/100/1000 Base-T applications. These devices switch the signals from two interface transformers and connect the signals to a sin- gle 10/100/1000 Base-T Ethernet PHY, simplifying docking station design and reducing manufacturing costs. The MAX4890/MAX4891/MAX4892 can also route signals from a common interface transformer to two different boards in board-redundancy applications. The MAX4890/MAX4891/MAX4892 switches provide an extremely low capacitance and on-resistance to meet Ethernet insertion and return-loss specifications. The MAX4891/MAX4892 feature one and three built-in LED switches, respectively. The MAX4890/MAX4891/MAX4892 are available in space-saving 32- and 36-lead TQFN packages, significantly reducing the required PC board area. These devices operate over the -40°C to +85°C tem- perature range. Applications Notebooks and Docking Stations Servers and Routers with Ethernet Interfaces Board-Level Redundancy Protection SONET/SDH Signal Routing T3/E3 Redundancy Protection Video Switching
The MAX4890, MAX4891 and MAX4892 are high‑speed analog switches designed for 10/100/1000 Base‑T Ethernet LAN applications such as notebooks, docking stations, servers and board‑level redundancy. They route signals from interface transformers to Ethernet PHYs, offering low capacitance and on‑resistance to meet Ethernet insertion‑loss requirements. The devices are offered in compact 32‑ and 36‑lead TQFN packages and operate from –40 °C to +85 °C.
Key electrical characteristics include a single supply voltage of 3.0 V to 3.6 V, typical on‑resistance of 4 Ω, ultra‑low on‑capacitance of 6.5 pF, a –3 dB bandwidth of 1 GHz, and a maximum quiescent current of 450 pA. The MAX4891 and MAX4892 incorporate one and three built‑in LED switches respectively for status indication.
| Supply‑Voltage Range | 3.0 V to 3.6 V |
|---|---|
| Operating Temperature Range | -40 °C to +85 °C |
| On‑Capacitance (Con) | 6.5 pF (typ) |
| Bandwidth (‑3 dB) | 1 GHz |
| Quiescent Supply Current | 450 pA (max) |
| Built‑in LED Switches | MAX4891: 1, MAX4892: 3 |
They operate from –40 °C to +85 °C.
A single supply voltage of 3.0 V to 3.6 V is required.
The MAX4891 includes one built‑in LED switch.