64 CSA (±1.6 fC), S&H, ADC in every channel, outputs digitized pulse height and trigger

The VATA451 is a 64 channel front-end readout for silicon strip and silicon radiation sensors. The circuit was used in the Focusing Optics X-ray Solar Imager (FOXSI). Each CSA is followed by a slow and a fast shaper. The fast shaper signals are compared with a global trigger threshold. Each channel has a 10-bit ADC with latches. The digitized pulseheight can be read out from a digital multiplexer. A common mode (CM) detector is included on-chip.

Keywords: Focusing optics x-ray solar imager (FOXSI)

Product Features

ApplicationImaging, Spectroscopy, Tracking
Number of inputs64
Input charge range-1.6 fC to +1.6 fC
Shaping time4 μs (VA), 0.6 μs/1.2 μs programmable (TA)
Nominal capacitive load5 pF
Equivalent Noise Charge (ENC)30e + 7e/pF
Trigger thresholdAdjustable
Trigger outputsCommon trigger output for all channels
OutputsSerial digitized pulse height
Test and calibrationCalibration circuit and ADC test circuit
Power consumption1 mW / channel


  • S. Ishikawa, et al. 2011, "Fine-Pitch Semiconductior Detector for the FOXSI Mission", IEEE Transactions on Nuclear Science, vol. 58, issue 4, pp. 2039-2046, DOI: 10.1109/TNS.2011.2154342