AD6623

The AD6623 is a 4-channel Transmit Signal Processor (TSP) that creates high bandwidth data for Transmit Digital-to-Analog Converters (TxDACs) from baseband data provided by a Digital Signal Processor (DSP). Modern TxDACs have achieved suffi- ciently high sampling rates, analog bandwidth, and dynamic range to create the first Intermediate Frequency (IF) directly. The AD6623 synthesizes multicarrier and multistandard digital signals to drive these TxDACs. The RAM-based architecture allows easy reconfiguration for multimode applications. Modulation, pulse- shaping and anti-imaging filters, static equalization, and tuning functions are combined in a single, cost-effective device. Digital IF signal processing provides repeatable manufacturing, higher accuracy, and more flexibility than comparable high dynamic range analog designs.

The AD6623 has four identical digital TSPs complete with synchro- nization circuitry and cascadable wideband channel summation. AD6623 is pin compatible to AD6622 and can operate in AD6622- compatible control register mode.

The AD6623 utilizes a 3.3 V I/O power supply and a 2.5 V core power supply. All I/O pins are 5 V tolerant. All control registers and coefficient values are programmed through a generic micro- processor interface. Intel and Motorola microprocessor bus modes are supported. All inputs and outputs are LVCMOS compatible.