ProMos V55C2256164VB 256Mbit MOBILE SDRAM 2.5 VOLT FBGA PACKAGE 16M X 16 V55C2256164VB 256Mbit MOBILE SDRAM 2.5 VOLT FBGA PACKAGE 16M X 16 is a high performance mobile SDRAM in the V55 series. It supports up to 143MHz clock speed and has a four-channel, 4Mbit x 16 organization.