TLC320AC02C_15 Datasheet, PDF (7/86 Pages) Texas Instruments – Single-Supply Analog Interface Circuit

1 Introduction
The TLC320AC02^† analog interface circuit (AIC) is an audio-band processor that provides an
analog-to-digital and digital-to-analog input/output interface system on a single monolithic CMOS chip. This
device integrates a band-pass switched-capacitor antialiasing input filter, a 14-bit-resolution
analog-to-digital converter (ADC), a 14-bit-resolution digital-to-analog converter (DAC), a low-pass
switched-capacitor output-reconstruction filter, (sin x)/x compensation, and a serial port for data and control
transfers.
The internal circuit configuration and performance parameters are determined by reading control
information into the eight available data registers. The register data sets up the device for a given mode of
operation and application.
The major functions of the TLC320AC02 are:
1. To convert audio-signal data to digital format by the ADC channel
2. To provide the interface and control logic to transfer data between its serial input and output
terminals and a digital signal processor (DSP) or microprocessor
3. To convert received digital data back to an audio signal through the DAC channel
The antialiasing input low-pass filter is a switched-capacitor filter with a sixth-order elliptic characteristic. The
high-pass filter is a single-pole filter to preserve low-frequency response as the low-pass filter cutoff is
adjusted. There is a three-pole continuous-time filter that precedes this filter to eliminate any aliasing caused
by the filter clock signal.
The output-reconstruction switched-capacitor filter is a sixth-order elliptic transitional low-pass filter followed
by a second-order (sin x)/x correction filter. This filter is followed by a three-pole continuous-time filter to
eliminate images of the filter clock signal.
The TLC320AC02 consists of two signal-processing channels, an ADC channel and a DAC channel, and
the associated digital control. The two channels operate synchronously; data reception at the DAC channel
and data transmission from the ADC channel occur during the same time interval. The data transfer is in
2s-complement format.
There are three basic modes of operation available: the stand-alone analog-interface mode, the
master-slave mode, and the linear-codec mode. In the stand-alone mode, the TLC320AC02 generates the
shift clock and frame synchronization for the data transfers and is the only AIC used. The master-slave mode
has one TLC320AC02 as the master that generates the master-shift clock and frame synchronization; the
remaining AICs are slaves to these signals. In the linear-codec mode, the shift clock and the frame-
synchronization signals are externally generated and the timing can be any of the standard codec-timing
patterns.
Typical applications for this device include modems, speech processing, analog interface for DSPs,
industrial-process control, acoustical-signal processing, spectral analysis, data acquisition, and
instrumentation recorders.
The TLC320AC02C is characterized for operation from 0°C to 70°C and the TLC320AC02I is characterized
for operation from –40°C to 85°C.
† _{The TLC320AC02 is functionally equivalent to the TLC320AC01 and differs in the electrical specifications as shown}
in Appendix C.
1–1