This is the PCB design for the DAC900E [1] from Texas Instruments, a 165 MSPS DAC with 10 bits resolution.
The design is mainly based on the schematic from the example given in the datasheet.
This breakout board connects to the DE0 Evaluation board from ALTERA.
As a transformer a Mini Circuit ADT1-1WT [2] is used.
The schematic looks the following:
The board design looks like:
It should be noted that Analog and Digital ground are separated.
The DAC was tested with an oscilloscope. The clock frequency of the DAC is 160 MHz and a sine wave is generated.
The oscilloscope is terminated with 50 Ohm. A 10 MHz sine wave is generated.
The left screenshot shows the wave from the DAC directly connected. In the right picture a reconstruction filter @ 15 MHz is connected between the DAC and the scope in order to remove higher frequencies. The wave gets very smooth. Good precision in frequency is achieved.
Function | GPIO Pin | DE0 GPIO1 Pin No |
DAC_BIT9 | GPIO_D0 | AA20 |
DAC_BIT8 | GPIO_D1 | AB20 |
DAC_BIT7 | GPIO_D2 | AA19 |
DAC_BIT6 | GPIO_D3 | AB19 |
DAC_BIT5 | GPIO_D4 | AB18 |
DAC_BIT4 | GPIO_D5 | AA18 |
DAC_BIT3 | GPIO_D6 | AA17 |
DAC_BIT2 | GPIO_D7 | AB17 |
DAC_BIT1 | GPIO_D8 | Y17 |
DAC_BIT0 | GPIO_D9 | W17 |
DAC_CLK | GPIO_CLKOUT0 | R16 |
The design files can be downloaded from GitHub
https://github.com/digibird1/DAC900E
It can be checked out with:
git clone https://github.com/digibird1/DAC900E
[1] http://www.ti.com/lit/ds/symlink/dac900.pdf
[2] http://www.minicircuits.com/pdfs/ADT1-1WT.pdf
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