Fig. 1 Functional Block Diagram
ASNT2121-KMM is a low power and high-speed digital 1 to 4 deserializer/demultiplexer (DMUX) that functions seamlessly over data rates (fbit) ranging from DC to its maximum frequency. The main function of the part is to demultiplex an incoming high speed serial differential CML data bit stream dp/dn running at a bit rate of fbit into 4 parallel data channels q0p/q0n, q1p/q1n, q2p/q2n, q3p/q3n running at a bit rate of fbit/4. Differential or single-ended full-rate clock cep/cen must be provided by an external source for the part to function properly.
The parallel words and clock divided by 4 c4op/c4on are transmitted through CML output interfaces. The clock and data inputs are phase matched to each other resulting in very little relative skew over the operating temperature range of the device. All I/O stages are back terminated to vcc with on-chip 50Ω resistors and may be used in either DC or AC coupling modes. In the first mode, the input signal’s common mode voltage should comply with specifications shown in the electrical characteristics table within the part’s datasheet. In the second mode, the input termination provides the required common mode voltage automatically. Differential DC signaling is recommended for optimal performance, and the part uses a single +3.3V or -3.3Vpower supply.