Noise analysis and optimization of VCII-based SiPM interface circuit

Abstract

Recently, second generation voltage conveyor (VCII)-based transimpedance amplifiers (TIAs) have begun to find their way in different applications, among which, silicon photomultipliers (SiPMs) interfacing circuitry. There are many advantages which make VCII-based TIAs attractive over conventional circuits: the intrinsic low impedance at VCII current input Y port is very helpful to mitigate the effect of high value sensor capacitance and provides fast response time; the achieved bandwidth is high and due to current mode operation; the circuits enjoy the low-voltage low-power features. As signal-to-noise ratio is a crucial parameter in SiPMs interface circuit applications, here we consider the noise specifications and optimization of VCII-based SiPM interface circuits. The noise model of VCII is introduced and equivalent noise of a VCII-based interface circuit is derived. Methods to optimize trade-offs existing between key parameters including power consumption, gain and noise performance are discussed. Simulation results are also provided showing a considerable reduction of two orders of magnitude in most of the noise performances when compared to the previous work while preserving other performance parameters.

A Survey on Current-Mode Interfaces for Bio Signals and Sensors

“…The ideal voltage–current relationships of a VCII are the following: where, again, and are unitary gains and, depending on whether it is or , we distinguish between VCII+ and VCII−, respectively. A simple practical implementation at transistor level of a VCII can be found in [ 73 ], while more advanced architectures proposed are a low-voltage, high-drive VCII that permits high current drive capability at the X port [ 74 ] and rail-to-rail VCIIs, presented in [ 54 , 75 ]. As for the CCII, all these practical implementations of the VCII suffer from non-ideal values of the port impedances and non-unitary gains.…”

“…Most importantly, this current-mode solution exhibits, for the first time, the interesting property that the achieved gain is independent of bandwidth because, differently from operational amplifiers, the VCII has a constant bandwidth. If the noise minimization is also carried out at transistor level using an appropriate internal structure for the VCII optimum noise performance can be obtained, and the study carried out in [ 73 ] presents the main guidelines that must be considered for an optimum design. Finally, we must note that even though it is reasonable to assume that similar performances can be obtained using CCIIs, a corresponding study on the implementation of a CCII-based interface for SiPMs is missing.…”

Flipped Voltage Follower-Based Voltage Conveyors: Investigation and Possible Enhancements

“…In order to produce and sustain sinusoidal oscillations, the transfer function in (7) must satisfy the Barkhausen criteria, and therefore, the frequency of oscillation as well as the start-up oscillation condition will be…”

Reconfigurable Voltage-Mode First-Order Multifunction Filter Employing Second-Generation Voltage Conveyor (VCII) With Complete Standard Functions and Electronically Controllable Modification

“…It is obvious that a new active building block with low-impedance voltage output capability is useful for many analog signal processing applications like analog filters, inverse filters, and sinusoidal oscillators, etc. Second-generation voltage conveyor (VCII) is a versatile block [8], [9], [10], which is the dual of CCII, and it has been used for applications [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31] requiring lowimpedance voltage output. This new ABB has an advantage over CCII and previous current-mode ABBs since it can process signals in the current domain and output signals in both voltage and current.…”