Title :
Analysis of 1/f noise in CMOS preamplifier with CDS circuit
Author :
Lee, Tae Hoon ; Cho, Gyuseong ; Kim, Hee Joon ; Lee, Seung Wook ; Lee, Wanno ; Han, Sang Hyo
Author_Institution :
Dept. of Nucl. Eng., Korea Adv. Inst. of Sci. & Technol., Taejon, South Korea
Abstract :
Noise of CMOS charge sensitive preamplifier (CSA) and correlated-double sample and hold (CDS) circuit matching a capacitive source is calculated to analyze the relative portions of thermal and 1/f noise. In most radiation detector systems, PMOS transistor is used as an input transistor because of its lower 1/f noise than that of NMOS. But to study the 1/f noise reduction action of CDS circuit in the 1/f noise dominant condition, NMOS transistor is deliberately chosen as the input transistor of CSA. The theoretical minimum number of equivalent noise charge (ENC) that can be achieved in this system is about 1700 rms electrons for a 5pF detector capacitance. In order to demonstrate the theoretical analysis, a chip of CSA and CDS was designed in a 0.5μm CMOS technology. The main amplifier is a differential input single-ended folded cascode and its measured gain bandwidth is over 5MHz. The measured ENC´s of CSA-Shaper and CSA-CDS are 2105 and 3046 noise electrons, respectively.
Keywords :
1/f noise; CMOS analogue integrated circuits; MOSFET; nuclear electronics; preamplifiers; sample and hold circuits; 1/f noise; CMOS charge sensitive preamplifier; NMOS transistor; capacitive source; correlated-double sample and hold circuit; differential input single-ended folded cascode; equivalent noise charge; gain bandwidth; radiation detector systems; thermal noise; CMOS technology; Capacitance; Circuit noise; Electrons; MOS devices; MOSFETs; Noise reduction; Preamplifiers; Radiation detectors; Semiconductor device measurement;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2001 IEEE
Print_ISBN :
0-7803-7324-3
DOI :
10.1109/NSSMIC.2001.1009676