Trimmable bandgap reference circuit with exponential curvature compensation

This paper proposes an improved exponential curvature-compensated bandgap reference circuit to exploit the exponential relationship between the current gainβof the bipolar junction transistor(BJT)and the temperature as well as reduce the influence of resistance-temperature dependency.Considering the degraded circuit performance caused by the process deviation,the trimmable module of the temperature coefficient(TC)is introduced to improve the circuit stability.The circuit has the advantages of simple structure,high linear stability,high TC accuracy,and trimmable TC.It consumes an area of 0.09 mm^(2)when fabricated by using the 0.25-μm complementary metal-oxide-semiconductor(CMOS)process.The proposed circuit achieves the simulated power supply rejection(PSR)of about-78.7 dB@1 kHz,the measured TC of~4.7 ppm/℃over a wide temperature range from-55℃to 125℃with the 2.5-V single-supply voltage,and the tested line regulation of 0.10 mV/V.Such a high-performance bandgap reference circuit can be widely applied in high-precision and high-reliability electronic systems.

A 2.2-V 2.9-ppm/℃BiCMOS bandgap voltage reference with full temperature-range curvature-compensation

A high precision high-order curvature-compensated bandgap reference compatible with the standard Bi-CMOS process,which uses a simple structure to realize a novel exponential curvature compensation in lower temperature ranges,and a piecewise curvature correction in higher temperature ranges,is presented.Experiment results of the proposed bandgap reference implemented with a 0.6-μm BCD process demonstrate that a temperature coefficient of 2.9 ppm/℃is realized at a 3.6-V power supply,a power supply rejection ratio of 85 dB is achieved,and the line regulation is better than 0.318 mV/V for 2.2-5 V supply voltage dissipating a maximum supply current of 45μA.The active area of the presented bandgap reference is 260×240μm;.

SCHMM-based Compensation for the Random Delays in Networked Control Systems

In order to compensate the network-induced random delays in networked control systems（NCSs）, the semi-continuous hidden Markov model（SCHMM） is introduced in this paper to model the controller-to-actuator（CA） delay in the forward network channel. The expectation maximization algorithm is used to obtain the optimal estimation of the model s parameters, and the Viterbi algorithm is used to predict the CA delay in the current sampling period. Thus, the predicted CA delay and the measured sensor-tocontroller（SC） delay in the current sampling period are used to design an optimal controller. Under this controller, the exponentially mean square stability of the NCS is guaranteed, and the SC and CA delays are compensated. Finally, the effectiveness of the method proposed in this paper is demonstrated by a simulation example. Moreover, a comparative example is also given to illustrate the superiority of the SCHMM-based optimal controller over the discrete hidden Markov model（DHMM）-based optimal controller.