Title :
Low noise charge sensitive preamplifier using drain current feedback
Author :
Olschner, F. ; Lund, J.C.
Author_Institution :
Radiat. Monitoring Devices, Inc., Watertown, MA, USA
Abstract :
A method of charge-sensitive amplifier feedback is described, in which the input FET drain current is controlled by the preamplifier output voltage producing stable operation. The circuit design has the benefit of eliminating the feedback resistor, thereby eliminating its parallel white and 1/f noise components. The circuit is simple, requiring no specialized FET designs. The FETs may remain in their packaged state because they do not have to be light sensitive for purposes of reset. Measurements were made to compare this feedback mode to that using resistor feedback. The noise level of the drain current feedback amplifier was observed to be substantially less than the resistor feedback at all shaping times used
Keywords :
feedback; field effect transistor circuits; nuclear electronics; preamplifiers; 1/f noise components; charge-sensitive amplifier feedback; circuit design; drain current feedback; feedback resistor; input FET drain current; low noise preamplifier; noise level; packaged state; preamplifier output voltage; reset; shaping times; stable operation; white noise; Circuit noise; Circuit synthesis; FETs; Noise level; Operational amplifiers; Output feedback; Packaging; Preamplifiers; Resistors; Voltage control;
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference, 1992., Conference Record of the 1992 IEEE
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-0884-0
DOI :
10.1109/NSSMIC.1992.301262
