AD1868

a FEATURES Dual Serial Input, Voltage Output DACs Single +5 V Supply 0.004% THD+N (typ) Low Power: 50 mW (typ) 108 dB Channel Separation (min) Operates at 8؋ Oversampling 16-Pin Plastic DIP or SOIC Package APPLICATIONS Portable Compact Disc Players Portable DAT Players and Recorders Automotive Compact 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 AD1868 16 VBL – + 14 VOL VREF 15 VS 18-BIT SERIAL REGISTER DL 3 CK 4 13 NRL DR 5 LR 6 18-BIT SERIAL REGISTER 12 AGND VREF + 11 NRR DGND 7 18-BIT DAC – 10 VOR VS PRODUCT DESCRIPTION VBR 8 9 The AD1868 is a complete 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 throug...