Terasic TSOM, Manual

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TSoM Evaluation
Kit User Manual 32
www.terasic.com
July 26, 2019
The LTC2308 is a low noise, 500ksps, 8-channel, 12-bit ADC with a SPI/MICROWIRE compatible
serial interface. This ADC includes an internal reference and a fully differential sample-and-hold
circuit to reduce common mode noise. The internal conversion clock allows the external serial
output data clock (SCK) to operate at any frequency up to 40MHz.
It can be configured to accept eight input signals at inputs ADC_IN0 through ADC_IN7. These
eight input signals are connected to a 2x5 header, as shown in
Figure 5-6 .
Figure 5-6 Signals of the 2x5 Header
These Analog inputs are shared with the Arduino's analog input pin (ADC_IN0 ~ ADC_IN5),
Figure 5-7 shows the connections between the FPGA, 2x5 header, Arduino Analog input, and the
A/D converter.
More information about the A/D converter chip is available in its datasheet. It can be found on
manufacturer’s website or in the directory \Datasheet\ADC of TSoM Based Board system CD.
Figure 5-7 Connections between the FPGA, 2x5 header, and the A/D converter
Table 5-6 Pin Assignment of ADC
Signal Name
260-pin Edge Connector
Pin No.
FPGA Pin No. Description I/O Standard
ADC_CONVST PIN_84 PIN_Y19 Conversion Start 3.3V
ADC_SCK PIN_82 PIN_AA20 Serial Data Clock 3.3V
ADC_SDI PIN_96 PIN_AA13
Serial Data Input
(FPGA to ADC)
3.3V