AD7847

a FEATURES Two 12-Bit MDACs with Output Amplifiers 4-Quadrant Multiplication Space-Saving 0.3" , 24-Lead DIP and 24-Terminal SOIC Package Parallel Loading Structure: AD7847 (8 + 4) Loading Structure: AD7837 APPLICATIONS Automatic Test Equipment Function Generation Waveform Reconstruction Programmable Power Supplies Synchro Applications LC2MOS Complete, Dual 12-Bit MDACs AD7837/AD7847 FUNCTIONAL BLOCK DIAGRAMS VDD MS INPUT LATCH LS INPUT LATCH 8 12 RFBA VOUTA AGNDA RFBB AD7837 4 DAC LATCH A VREFA VREFB DB0 DB7 LDAC CS WR A0 CONTROL LOGIC 4 DAC A DAC B 12 DAC LATCH B 8 LS INPUT LATCH MS INPUT LATCH VOUTB AGNDB GENERAL DESCRIPTION A1 The AD7837/AD7847 is a complete, dual, 12-bit multiplying digital-to-analog converter with output amplifiers on a monolithic CMOS chip. No external user trims are required to achieve full specified performance. Both parts are microprocessor compatible, with high speed data latches and interface logic. The AD7847 accepts 12-bit parallel data which is loaded into the respective DAC latch using the WR input and a separate Chip Select input for each DAC. The AD7837 has a double-buffered 8-bit bus interface structure with data loaded to the respective input latch in two write operations. An asynchronous LDAC signal on the AD7837 updates the DAC latches and analog outputs. The output amplifiers are capable of developing ± 10 V across a 2 kΩ load. They are internally compensated with low input offset voltage due to laser trimming at wafer leve...