The MAX3840 is a MAXIM high-performance dual 2×2 asynchronous crosspoint switch for SDH/SONET DWDM and other high-bandwidth data switching applications, suitable for OC-48 systems with forward error correction. It features high bandwidth, fully differential signal path, which minimizes jitter accumulation, crosstalk and signal skew. Each 2×2 crosspoint switch can fan out and/or multiplex up to 2.7Gbps data and 2.7GHz clock signals. All inputs and outputs are compatible with current mode logic (CML) and can be easily adapted to interface with an AC-coupled LVPECL signal. When not used, each CML output stage can be powered down with an enable control to conserve power. Typical power consumption is 460mW with all outputs enabled. The MAX3840 is compatible with the MAX3876 2.5Gbps clock and data recovery (CDR) circuit. The MAX3840 is available in a 32-pin exposed-pad QFN package (5mm×5mm footprint) and operates from a +3.3V supply over a temperature range of -40°C to +85°C.
The MAX3840 is a dual 2 × 2 asynchronous crosspoint switch designed for high‑speed data switching applications such as SDH/SONET, DWDM, and backplane interconnects. It operates from a single +3.3 V supply, consumes about 460 mW with all outputs enabled, and offers low jitter, low skew, and a fast 100 ps output edge.
Key features include CML input/output compatibility, power‑down control for unused outputs, 2 ps rms random jitter, 7 ps deterministic jitter, 6 ps channel‑to‑channel skew, and a 32‑pin TQFN package. The datasheet provides absolute maximum ratings, electrical characteristics, pin descriptions, routing tables, and layout recommendations.
| Supply Voltage (VCC) | +3.3 V |
|---|---|
| Maximum Data Rate | 2.7 Gbps |
| Typical Power Consumption | 460 mW |
| Random Jitter | 2 ps rms |
| Deterministic Jitter | 7 ps p‑p |
| Channel‑to‑Channel Skew | 6 ps |
| Output Edge Speed | 100 ps |
| Package Type | 32‑pin TQFN |
| Transistor Count | 1200 |
| Process Technology | Bipolar (SiGe) |
The device operates from a single +3.3 V supply.
Typical power consumption is 460 mW when all outputs are enabled.
Each crosspoint can handle up to 2.7 Gbps of data.
The device is offered in a 32‑pin TQFN package.