Readout and Signal Conditioning for a Linear Pyroelectric Array.

The requirement for low-cost infrared sensors for a range of applications has led to the development of linear pyroelectric detector arrays of up to 64 elements, integrated with MOSFET readout electronics and low-microphony packaging to give compact and easy-to-use infrared detectors operating at ambient temperatures in the 8-14 micron waveband. Along with these detectors, the necessary signal conditioning techniques have been developed, in order that the best system performance can be obtained whilst maintaining the aims of low cost, low power, and small size. The sensor system described here uses the VX 8-647 detector, developed under DCVD contract at Philips components Ltd. This detector is a 64 element ceramic pyroelectric array, with fully reticulated elements and with thermal and vibration isolation by means of a membrane structure. A custom MOSFET readout chip and standard hybrid components within the detector package make interfacing to the detector array very straightforward. The signal conditioning electronics is designed to be low power at low cost, making maximum use of analogue and digital CMOS components. The sensor is configured to be battery powered and transmit data by means of a serial data link. A measured NEDT of 0.25K at 50 Hz line rate is achieved, which accords well with the theoretical predictions. keywords: Great Britain. (fr)