The MAX4670 is an integrated T1/E1/J1 analog protection switch for 1+1 and N+1 line-card redundancy applications. It protects two T1/E1/J1 ports by combining eight SPDT switches in a single package. The switch is optimized for high-return loss and pulse-template performance in T1/E1/J1 long-haul and short-haul applications. The part offers built-in chip-side surge protection capability for short-haul intrabuilding applications. The MAX4670 replaces two diode arrays or two transient voltage suppressors (TVSs) and four dual-SPDT relays, significantly reducing board space and simplifying PC board routing. The MAX4670 pinout is targeted for T1/E1/J1 applications, resulting in a simplified layout when interfacing with standard line transformers and line interface units (LIUs). The MAX4670 has four 1.0Ω (max) on-resistance switches with 60pF/40pF on-/off-capacitances for interfacing to the LIU transmitter outputs. The MAX4670 also includes four 10Ω (max) on-resistance switches with low 24pF/12pF on-/off-capacitances for interfacing to the LIU receiver inputs. Four logic inputs control the receive/transmit pairs, in addition to a SWITCH input that connects all switches to the system’s protection bus. The MAX4670 operates from a single +2.7V to +3.6V supply and is available in 32-pin thermally enhanced TQFN package. The MAX4670 is specified over the -40°C to +85°C operating temperature range.
The MAX4670 provides protection for two T1/E1/J1 ports by integrating eight SPDT switches in a 32‑pin TQFN package. It is optimized for both short‑haul intrabuilding and long‑haul line‑card redundancy applications, offering low on‑resistance and low capacitance for both transmit and receive paths.
The device operates from a single 2.7 V to 3.6 V supply, supports a temperature range of –40 °C to +85 °C, and includes chip‑side surge protection compliant with IEC 61000‑4‑5 Class 2. It is suitable for use with standard line transformers and LIUs in optical multiplexers, edge routers, and other multiservice equipment.
| Supply Voltage Range | 2.7 V to 3.6 V |
|---|---|
| Operating Temperature Range | -40 °C to +85 °C |
| On‑Resistance (Transmit Path, typical) | 0.7 Ω |
| On‑Capacitance (Transmit Path) | 60 pF (on) / 40 pF (off) |
| Surge Protection Rating | IEC 61000‑4‑5 Class 2 (±1 kV) |
The device operates from a single supply voltage of 2.7 V to 3.6 V.
It is specified for operation from –40 °C up to +85 °C.
The MAX4670 combines eight SPDT switches in a single package.
The typical on‑resistance in the transmit path is 0.7 Ω.