A programmable, low noise, multichannel ASIC for readout of pixelated amorphous silicon arrays

Pixelated amorphous silicon arrays used for detecting X-rays have a number of special requirements for the readout electronics. Because the pixel detector is a high-density array, custom integrated circuits are very desirable for reading out the column signals and addressing the rows of pixels to be read out. In practice, separate chips are used for readout and addressing. This paper discusses a custom integrated circuit for processing the analog column signals. The chip has 32 channels of low-noise integrators followed by sample and hold circuits which perform a correlated double sample. The chip has several programmable features including gain, bandwidth, and readout configuration.