Research and development of a high-performance differential-hybrid charge sensitive preamplifier. (February 2017)

• Record Type: Journal Article
• Authors: Zeng, Guoqiang; Hu, Chuanhao; Wei, Shilong; Yang, Jian; Li, Qiang; Ge, Liangquan; Tan, Chengjun
• Is Part Of: Applied radiation and isotopes. Volume 120(2017:Feb.)
• Page Start: 95
• Page End: 100
• Publication Date: 2017-02
• Subjects: Charge-sensitive preamplifier -- Differential hybrid amplifier -- Folded cascode-bootstrap; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2016.12.006
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: A differential-hybrid charge sensitive preamplifier (CSP) was designed by taking a monolithic dual N-Channel Junction Field-effect Transistor (JFET) and a high-speed, low-noise, operational amplifier as the core parts. Input-stage of the circuit employs low-noise differential dual JFET, which ensures high input impedance and low noise. The differential dual transistor makes the quiescent point of the first-stage differential output stable, which is convenient for connecting with the post stage high-speed operational amplifier. Broadband could be amplified by connecting to the double differential dual transistors through the folded cascode-bootstrap. The amplifying circuit which replaces the interstage and post stage discrete components of a traditional CSP with integrated operational amplifier is simpler and more reliable. It simplifies the design of the quiescent point, gives full play to advantages of releasing large open-loop gain, and improves charge-voltage conversion gain stability. Particularly, the charge-voltage conversion gain is larger under a smaller feedback capacitor, thus enabling to gain better signal-noise ratio. The designed CSP was tested, reporting 3.3×10 13 V/C charge sensitivity, about 90 ns rise time of signals, 35:1 signal-noise ratio to gamma-rays of 137 Cs (662 keV) and a 0.023 fC/pF noise slope. Gamma-rays of 241 Am (59.5 keV) were measured by the BPX66 detector and the designed CSP under room temperature, providing 1.97% energy resolution. Highlights: A new differential-hybrid type charge sensitive preamplifier for high-resolution spectrometry survey system. The input-stage circuit is connected through differential folded cascode bootstrapping manner. The differential-hybrid charge sensitive preamplifier has excellent temperature characteristic.