NI PXI-2541 PXI RF Matrix Switch Module

The National Instruments PXI-2541 is an 8 × 12 RF matrix switch module designed for complex signal routing in automated test equipment and RF signal management systems. This 96-crosspoint module features a non-blocking architecture enabling simultaneous connection of any row to any column, with reed relays using rhodium contacts rated for 1 × 10⁷ mechanical cycles. Operating to 300 MHz, the PXI-2541 delivers 75 dB isolation, with typical crosstalk below −35 dB. The module supports up to 10 W RF power per channel in a 50 Ω system, with simultaneous operation at maximum power limited to 3 channels on standard PXI or 5 on PXIe. Fast relay switching—maximum 0.25 ms operate and release times—combined with <6 ns propagation delay and <2.0 ns channel-to-channel skew on signal paths, enables precise timing-critical test configurations. MCX connectors provide 28 I/O points. Row Out connectors can cascade with Row In connectors of additional modules to expand the matrix horizontally, creating configurations such as 8×24 or 8×36 without redesign constraints.

– Technical Specifications

• Matrix Configuration: 8 × 12 topology, 96 crosspoints
• Relay Type: Reed relays, rhodium contact material
• Relay Life: 1 × 10⁷ cycles (mechanical, typical)
• Characteristic Impedance: 50 Ω nominal
• Maximum Switching Voltage: 60 V DC; 42.5 V RMS AC; 42.4 V peak AC
• Maximum Switching/Carry Current: 0.5 A per channel
• Maximum Switching Power: 10 W per channel
• Maximum RF Power (50 Ω): 10 W per channel at frequencies ≤300 MHz
• Simultaneous Channels at Max RF Power: 3 (PXI); 5 (PXIe)
• Path Resistance: <2.1 Ω initial, ≥3.1 Ω end-of-life (typical)
• Insertion Loss (≤300 MHz): <3 dB row-to-column; <1 dB row-to-row (typical: <2.1 dB and <0.5 dB)
• VSWR (≤300 MHz): <2.2 row-to-column; <1.8 row-to-row (typical: <1.6 and 75 dB row-to-column; >30 dB row-to-row (typical)
• Crosstalk (≤300 MHz): <−35 dB typical
• Propagation Delay: <6 ns row-to-column; <1 ns row-to-row (typical)
• Channel-to-Channel Skew: <2.0 ns row-to-column; <0.1 ns row-to-row (typical)
• Maximum Operate Time: 0.25 ms
• Maximum Release Time: 0.25 ms
• Simultaneous Relay Drive Limit: 40 relays
• Connectors: 28 MCX jacks
• Power Consumption (PXI): 10 W at 5 V, 2 W at 3.3 V
• Power Consumption (PXIe): 10 W at 12 V, 2.5 W at 3.3 V

– Key Features

• Non-blocking matrix architecture for simultaneous multi-path connections
• Reed relay technology with rhodium contacts for long-term reliability
• RF performance rated to 300 MHz with 75 dB typical) and low crosstalk (<−35 dB typical)
• Fast switching with <0.25 ms settle time and <6 ns propagation delay
• Expandable column capacity via daisy-chain relay configuration
• PXI and PXIe form-factor compatibility

– Typical Applications

• Automated RF and microwave test systems
• Signal routing in multi-channel transceiver testing
• Component characterization and validation
• Production test environments requiring flexible matrix reconfiguration

– Compatibility & Integration

The PXI-2541 operates in standard PXI chassis and PXIe systems, consuming 10 W at 5 V (PXI) or 10 W at 12 V (PXIe). Multiple modules interconnect via Row Out–to–Row In connections to scale matrix dimensions for larger test configurations.