The 4MX0121V is a 12-bit bus switch / multiplexer (MUX) designed for 2.5 V supply voltage operation. The MUX is designed for operation in DDR3 and DDR4 memory bus systems. The 4MX0121V has a 1:2 switch or 2:1 multiplex topology with a 12-bit wide bus.

The 4MX0121V uses a high-speed switch architecture providing high bandwidth, low insertion loss, return loss, and very low propagation delay, allowing use in many applications requiring switching or mulitplexing of high-speed signals.


  • Host controller bus isolation from the DRAM memory during "save" and "restore" operations between DRAM and NVDIMM non-volatile memory
  • AC and DC parameters optimized for DDR4, enabling the highest possible memory channel performance for NVDIMMs even when intermixed with other DIMM types
  • 12-bit bus switch / multiplexer to best match the eight DQ pins and four DQS pins coming from each DRAM
  • VFBGA 48-pin package for a compact footprint that can replace data buffers on the DIMM for NVMDIMM applications
  • Make-before-break circuit to prevent glitches during switching operations

Product Options

Orderable Part ID Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Active FCCSP 48 C Yes Tray
Active FCCSP 48 C Yes Reel

Documentation & Downloads

Title Other Languages Type Format File Size Date
PCN# : A1811-01 Change of Bump and Assembly Location Product Change Notice PDF 25 KB
Memory Multiplexer Family Overview Overview PDF 807 KB
4MX0121V Switch/Multiplexer for DDR3/DDR4 NVDIMM Product Brief PDF 1.48 MB