TLC32046C

The TLC32046C, TLC32046I, and TLC32046M wide-band analog interface circuits (AIC) are a complete analog-to-digital and digital-to-analog interface system for advanced digital signal processors (DSPs) similar to the TMS32020, TMS320C25, and TMS320C30. The TLC32046C and TLC32046I offer a powerful combination of options under DSP control: three operating modes (dual-word [telephone interface], word, and byte) combined with two word formats (8 bits and 16 bits) and synchronous or asynchronous operation. TLC32046C provides a high level of flexibility in that conversion and sampling rates, filter bandwidths, input circuitry, receive and transmit gains, and multiplexed analog inputs are under processor control.

This AIC TLC32046C features a
   • band-pass switched-capacitor antialiasing input filter
   • 14-bit-resolution A/D converter
   • 14-bit-resolution D/A converter
   • low-pass switched-capacitor output-reconstruction filter.

The antialiasing input filter of TLC32046C comprises eighth-order and fourth-order CC-type (Chebyshev/elliptic transitional) low-pass and high-pass filters, respectively. The input filter is implemented in switchedcapacitor technology and is preceded by a continuous time filter to eliminate any possibility of aliasing caused by sampled data filtering. When low-pass filtering is desired, the high-pass filter can be switched out of the signal path. A selectable auxiliary differential analog input of TLC32046C is provided for applications where more than one analog input is required.

The output-reconstruction filter of TLC32046C is an eighth-order CC-type (Chebyshev/elliptic transitional low-pass filter) followed by a second-order (sin x)/x correction filter and is implemented in switched-capacitor technology. This filter is followed by a continuous-time filter to eliminate images of the sample data signal. The on-board (sin x)/x correction filter of TLC32046C can be switched out of the signal path using digital signal processor control.

The A/D and D/A architectures of TLC32046C  ensure no missing codes and monotonic operation. An internal voltage reference is provided to ease the design task and to provide complete control over the performance of the IC. The internal voltage reference  of TLC32046C is brought out to REF. Separate analog and digital voltage supplies and ground are provided to minimize noise and ensure a wide dynamic range. The analog circuit path contains only differential circuitry to keep noise to a minimum. The exception of TLC32046C is the DAC sample-and-hold, which utilizes pseudo-differential circuitry.

The TLC32046C is characterized for operation from 0 to 70, the TLC32046I is characterized for operation from 40 to 85, and the TLC32046M is characterized for operation from 55to 125.