2 channel 1GSPS 8 bit ADC card in FMC format using a Low Pin-Count connector

The following features are controllable by software:

    • Input signal range, coupling, termination and offset adjustment
    • Self-calibration
    • Sampling clock selection
    • Direction of external trigger in/out
    • ADC configuration and status
  • The offset adjustment does not clip the signal at the highest range (+/- 5V). That is why the “max input signal amplitude” has been specified as 10V, even though the selection of signal ranges only goes up to 5V. This way, a +10V pulse with -5V offset could still be digitised without clipping.
  • The sampling clock is derived from a voltage-controllable 125MHz clock source, controlled via an SPI DAC.
  • A copy of the 125MHz clock source is available on the FMC connector pins.
  • Software can select either one of the input channels to be sampled at 2 GSPS, by interleaving the 2 ADCs.
  • 50 Ohm input is protected from overload
  • 8 channel 12 bit I2C ADC monitors all local power supplies

This is a product that was developed in conjunction with CERN’s Open Hardware Repository and is available as a project here. The CERN Open Hardware Licence is to hardware what the free and open-source licences are to software. It defines the conditions under which a licensee will be able to use or modify the licensed material. It shares the same principles as free software or open-source software: anyone should be able to see the source – the design documentation in the case of hardware – study it, modify it and share it.



PCB Format:  VITA 57.1 FMC LPC

Connectors:  SMA

Sampling Rate:  1 GSPS (2GSPS in single channel mode)

Input Signal Type:  Single-ended

Resolution:  8 bits

Number of Channels:  2

Bandwidth (-3dB):  50Ω: DC to 400MHz (or better), 1MΩ: DC to 300MHz (or better)

Input Signal Coupling and Termination:  AC (8 Hz LF limit, after 50 Ω termination), DC-50Ω, DC-1MΩ

Input Signal Range:  +/- 50mV,  +/- 250mV,  +/- 500mV,  +/- 2.5V,  +/- 5V

Max Input Signal Amplitude:  +/- 10V

SNR:  > 40dB full bandwidth over all input ranges

ENOB:  > 6.5 full bandwidth over all input ranges

Offset Adjustment Range:  +/- 5V

Offset Adjustment Resolution:  16 bits

Offset Adjustment Accuracy:  < 1%

Additional I/O:  External TTL trigger in/out (bidirectional),  External 10MHz clock input

Self-calibration:  Automatic zeroing of offset and gain

ADC Interface:  serial/parallel LVDS

Temperature Sensor:  On I2C bus

FMC EEPROM:  32K bits type 24C32

Power Consumption:  Design estimation 9.6W