DEM-PCM1717-1
This demo board kit consist of a DEM-PCM1717 hardware board, together with an interface cable, for connecting the DEM-PCM1717 to power and connecting the software con- trol lines to an IBM-PC parallel port. DEM-PCM1717 also includes evaluation software, described later under Software Description. The interface cable connects to the connector CN2, a source of +5V and ground, and the parallel port of an IBM compatible PC. Figure 5 shows the block diagram and connection for the DEM-PCM1717-1.
DEM-DAI1717
DEM-DAI1717 is a complete evaluation fixture, including an SPDIF receiver, PCM1717 and an analog post low-pass filter DEM-DAI1717 also includes evaluation software.
PCM1717 contains features which can be programmed ex- ternally. These features include a 256-step digital attenuator, data interface format, word length, output format, etc. Refer to the PCM1717 data sheet for a complete description of these special functions.
PCM1717’s special functions are programmed via a 3-wire serial interface. This type of control is commonly referred to as serial or software control. The penalty for using this mode is that the DAC must be controlled via external microproces- sor or logic. But since most digital audio systems usually contain a microprocessor or micro controller, component count is not always increased.
DEM-DAI1717 utilizes the parallel port of an IBM-compat- ible PC to implement the 3-wire serial programming inter- face. The evaluation software runs on Windows© Operating System.
The DEM-DAI1717 evaluation board consists of three main sections or functions. The audio interface section consists of an electrical (RCA jack) or fiber optics connector to the SPDIF input. The input signal is processed into a standard 3- wire serial digital audio interface with the SPDIF receiver. The DAC section consists of the PCM1717E audio DAC and its associated circuitry. The active filter section uses an OPA2604 op amp to implement a 2nd-order filter for reduc- tion of out-of-band noise. Figure 6 shows the block diagram of the DEM-DAI1717 system board.
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