The VersaCOMM family of digital converters, the AD6623, is a 104 MSPS, four-channel transmit signal processor (TSP) designed for multi-mode, multi-standard wireless base station architectures. The AD6623 is used in the transmit signal path to process the signals from a general purpose DSP for input to a high-speed digital-to-analog converter. The AD6623 contains four identical digital TSPs complete with synchronization circuitry, and a cascadable wideband channel summation stage. On-chip tuners allow the relative phase and frequency for each of the four RF output carriers to be independently controlled. Each channel accepts input data from independent serial ports that may be connected directly to the serial port of the DSP devices. The RAM-based architecture of the AD6623 allows easy, on-the0fly, reconfiguration to accommodate multi-mode operation in compliance with both digital and analog air interface standards. The AD6623 supports GSM/EDGE, IS95, cdma2000 and UMTS cellular air standards. 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 and LVCMOS compatible.