We have developed the analog electronics of the ASTRO-E Hard X-ray Detector (HXD). The ASTRO-E is the fifth Japanese X-ray astronomy satellite scheduled for launch in 2000. Three experiments will be on board the satellite, one of which being the HXD. The detector consists of 16 units of well-type phoswich counters with silicon PIN diodes embedded therein, and covers the energy range of 10 ~600 keV with photon collecting area of about 350 cm ↑(2). The readout circuit for the HXD handles many signal channels (96 channels in total) under the limitation of power consumption and size set by the satellite. To meet the limitations, we have developed two types of bipolar semilcustom LSIs. One is the pulse-shape discriminator (PSD-LSI) for phoswich counters and the other is for silicon PIN diodes (PIN-LSI). The PSD-LSI selects clean GSO hits and reduces the off-aperture X-rays and internal background of the detector down to 10 ↑(-5) c/s/cm ↑(2)/keV. One PIN-LSI handles signals from two PLN diodes, each consisting f an amplifier, a peak-hold circuit, and a comparator to trigger the readout system. Test pieces of these LSIs meet the specifications such as power consumptions and linearities. Using PIN-LSI, we could successfully obtain X-ray spectrum from 24tAm with a PIN diode.
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