AD6622

The AD6622 comprises four identical digital Transmit Signal Processors (TSPs) complete with synchronization circuitry and cascadable wideband channel summation. An external digitalto-analog converter (DAC) is all that is required to complete a wide band digital up-converter. On-chip tuners allow the relative phase and frequency for each RF carrier to be independently controlled.

Each TSP has three cascaded signal processing elements: a RAM-programmable Coefficient interpolating Filter (RCF), a programmable Cascaded Integrator Comb (CIC) interpolating filter, and a Numerically Controlled Oscillator/tuner (NCO). The outputs of the four TSPs are summed and scaled on-chip.

In multichannel wideband transmitters, multiple AD6622s may be combined using the chip's cascadable output summation stage. Each channel provides independent serial data inputs that may be directly connected to the serial port of DSP chips. User programmable FIR filters can be used to filter linear inputs.

All control registers and coefficient values of AD6622 are programmed through a generic microprocessor interface. Two microprocessor bus modes are supported. All inputs and outputs are LVCMOS compatible. All outputs are LVCMOS and 5 V TTL compatible.