AD1879 Datasheet | Analog Devices

a Features Fully Differential Dual Channel Analog Inputs 103 d B Signal-to-Noise (AD1879 typ) - 98 d B THD+N (AD1879 typ) 0.001 d B Passband Ripple and 115 d B Stopband Attenuation Fifth-Order, 64 Times Oversampling ⌺⌬ Modulator Single Stage, Linear Phase Decimator 256 ؋ FS Input Clock APPLICATIONS Digital Tape Recorders Professional, DCC, and DAT A/V Digital Amplifiers CD-R Sound Reinforcement PRODUCT OVERVIEW LRCK BCK S0 64/32 DV High Performance 16-/18-Bit ⌺⌬ Stereo ADCs AD1878/AD1879- FUNCTIONAL BLOCK DIAGRAM 1 2 3 4 5 6 7 8 9 ANALOG CHIP D SERIAL OUTPUT INTERFACE DIGITAL CHIP SINGLE-STAGE, 4k-TAP FIR DECIMATION FILTER SINGLE-STAGE, 4k-TAP FIR DECIMATION FILTER 28 27 26 25 WCK DATA CLOCK S1 24 RESET 23 22 DGND DVDD AVSS1 AV AV DD DD DGND NC AV 1 21 20 19 18 17 16 15 AVSS2 2 1 AGND 10 The AD1879 is a two-channel, 18-bit oversampling ADC based on ∑∆ technology and intended primarily for digital audio applications. The AD1878 is identical to the 18-bit AD1879 except that it outputs 16-bit data words. Statements in this data sheet should be read as applying to both parts unless otherwise noted. Each input channel of these ADCs is fully differential. Each data conversion channel consists of a fifth order one-bit noise shaping modulator and a digital decimation filter. An on-chip voltage reference provides a voltage source to both channels stable over temperature and time. Digital output data from both channels is time-multiplexed to a single, flexible serial interface. The AD1878/AD1879 accepts a 256 × FS input master clock. Input signals are sampled at 64 × FS on switched-capacitors, eliminating external sample-and-hold amplifiers and minimizing the requirements for antialias filtering at the input. With simplified antialiasing, linear phase can be preserved across the passband. The AD1878/AD1879’s proprietary fifth-order differential switched-capacitor modulator architecture shapes the one-bit parator’s quantization noise...