AD1868 Datasheet | Analog Devices

a Features Dual Serial Input, Voltage Output DACs Single +5 V Supply 0.004% THD+N (typ) Low Power: 50 m W (typ) 108 d B Channel Separation (min) Operates at 8؋ Oversampling 16-Pin Plastic DIP or SOIC Package APPLICATIONS Portable pact Disc Players Portable DAT Players and Recorders Automotive pact Disc Players Automotive DAT Players Multimedia Workstations VL 1 LL 2 Single Supply Dual 18-Bit Audio DAC AD1868- FUNCTIONAL BLOCK DIAGRAM 18-BIT DAC 16 VBL - + 14 VOL VREF 15 VS 18-BIT SERIAL REGISTER 18-BIT SERIAL REGISTER 12 AGND VREF + 11 NRR DGND 18-BIT DAC - 10 VOR VS PRODUCT DESCRIPTION The AD1868 is a plete dual 18-bit DAC offering excellent performance while requiring a single +5 V power supply. It is fabricated on Analog Devices’ ABCMOS wafer fabrication process. The monolithic chip includes CMOS logic elements, bipolar and MOS linear elements, and laser-trimmed thin-film resistor elements. Careful design and layout techniques have resulted in low distortion, low noise, high channel separation, and low power dissipation. The DACs on the AD1868 chip employ a partially segmented architecture. The first three MSBs of each DAC are segmented into seven elements. The 15 LSBs are produced using standard R-2R techniques. The segments and R-2R resistors are laser trimmed to provide extremely low total harmonic distortion. The AD1868 requires no deglitcher or trimming circuitry. Low noise is achieved through the use of two noise-reduction capacitors. Each DAC is equipped with a high performance output amplifier. These amplifiers achieve fast settling and high slew rate, producing ± 1 V signals at load currents up to ± 1 m A. The buffered output signal range is 1.5 V to 3.5 V. Reference voltages of 2.5 V are provided, eliminating the need for “False Ground” networks. A versatile digital interface allows the AD1868 to be directly connected to all digital filter chips. Fast CMOS logic elements allow...