Fairchild Semiconductor – Two-port multiplexer for storage and multimedia cards and peripherals


The FSSD06 from Fairchild is a two-port multiplexer which enables the output from a host application processor, baseband processor or ASIC to be routed to multiple Secure Digital (SD), Secure Digital I/O (SDIO) or Multimedia Card (MMC) cards or peripherals.

The architecture includes the necessary bi-directional data and command transfer capability for single high-voltage cards, or for dual-voltage cards. The clock path for the FSSD06 is a uni-directional buffer with an integrated pull-up for its high-impedance mode.


The FSSD06 conforms to the specifications of the SD, SDIO and MMC standards.


  • 4Ω on-resistance
  • >120MHz toggle frequency
  • 9pF on-capacitance
  • 1μA maximum quiescent supply current


  • Portable devices
  • Media players
  • Storage devices
  • Computer peripherals
  • Wireless LAN cards
  • Broadband access cards