ICSSSTVA16857

The 14-bit ICSSSTVA16857 is a universal bus driver designed for 2.3V to 2.7V VDD operation and SSTL_2 I/O levels,except for the LVCMOS RESET# input.

Data flow from D to Q is controlled by the differential clock (CLK/CLK#) and a control signal (RESET#). The positive edge of CLK is used to trigger the data flow and CLK# is used to maintain sufficient noise margins where as RESET#, an LVCMOS asynchronous signal, is intended for use at the time of power-up only. ICSSSTVA16857 supports low-power standby operation. A logic level "Low" at RESET# assures that all internal registers and outputs (Q) are reset to the logic "Low" state, and all input receivers, data (D) and clock (CLK/CLK#) are switched off. Please note that RESET# must always be supported with LVCMOS levels at a valid logic state because VREF may not be stable during power-up.

To ensure that outputs are at a defined logic state before a stable clock has been supplied, RESET# must be held at a logic"Low" level during power up.

In the DDR DIMM application, RESET# is specified to be completely asynchronous with respect to CLK and CLK#.Therefore, no timing relationship can be guaranteed between the two signals. When entering a low-power standby state,the register will be cleared and the outputs will be driven to a logic "Low" level quickly relative to the time to disable the differential input receivers. This ensures there are no glitches on the output. However, when coming out of low-power standby state, the register will become active quickly relative to the time to enable the differential input receivers. When the data inputs are at a logic level "Low" and the clock is stable during the "Low"-to-"High" transition of RESET# until the input receivers are fully enabled, the design ensures that the outputs will remain at a logic "Low" level.