Single-Supply 16-Bit (Sigma Delta) Stereo ADC

The AD1877 is a stereo, 16-bit oversampling ADC based on Sigma Delta technology. This part is intended primarily for digital audio applications requiring a single 5 V power supply. Each single-ended channel consists of a fourth-order one-bit noise shaping modulator and a digital decimation filter. An on-chip voltage reference, stable over temperature and time, defines the full-scale range for both channels. Digital output data from both channels are time-multiplexed to a single, flexible serial interface. The AD1877 accepts a 256 × FS or a 384 × FS input clock and operates in both serial port "master" and "slave" modes. In slave mode, all clocks must be externally derived from a common source.

The flexible serial output port, which is configured with pin selections, produces data in two s-complement, MSB-first format. The input and output signals are TTL-compatible. Each 16-bit output word of a stereo pair can be formatted within a 32-bit field of a 64-bit frame as either right-justified, I2S-compatible, Word Clock controlled or left-justified positions. Both 16-bit samples can also be packed into a 32-bit frame, in left-justified and I2S-compatible positions.

The AD1877 is fabricated on a single monolithic integrated circuit using a 0.8 µm CMOS double polysilicon, double metal process, and is offered in a plastic 28-lead SOIC package. Analog and digital supply connections are separated to isolate the analog circuitry from the digital supply and reduce digital crosstalk. The AD1877 operates from a single 5 V power supply over the temperature range of 0°C to +70°C, and typically consumes less than 260 mW of power.

* Single 5 V Power Supply

* Single-Ended Dual-Channel Analog Inputs

* 92 dB (Typ) Dynamic Range

* 90 dB (Typ) S/(THD + N)

* 0.006 dB Decimator Pass-Band Ripple

* Fourth Order, 64X Oversampling Σ-Δ Modulator

* Three-Stage, Linear-Phase Decimator