LF2249

The LF2249 is a high-speed digital mixer comprised of two 12-bit multipliers and a 24-bit accumulator.

All multiplier inputs are user acces- sible, and each can be updated on every clock cycle.  The LF2249 utilizes a pipelined architecture with fully registered inputs and outputs and an asynchronous three-state output enable control for optimum flexibility.

Independent input register clock enables allow the user to hold the data inputs over multiple clock cycles.

Each multiplier input also includes a user-selectable 1-16 clock pipeline delay.  The output of each multiplier can be independently negated under user control for subtraction of prod- ucts.  The sum of the products can also be internally rounded to 16 bits during the accumulation process.

A separate 16-bit input port con- nected to the accumulator is included to allow cascading of multiple LF2249s.  Access to all 24 bits of the accumulator is gained by switching between upper or lower 16-bit words.

The accumulated output data is updated on every clock cycle.

All inputs and outputs of the LF2249 are registered on the rising edge of clock, except for OE.  Internal pipeline registers for all data and control inputs are provided to maintain synchronous operation between the incoming data and all available control functions.  The LF2249 oper-ates at a clock rate of 40 MHz over the full commercial temperature and supply voltage ranges.

Because of its flexibility, the LF2249 is ideally suited for applications such as image switching and mixing, digital quadrature mixing and modulating,FIR filtering, and arithmetic function and waveform synthesis.