The Design Of High Performance Piecewise Curvature Compensation Bandgap Voltage Reference

In recent years, with the fast iterative development of the smart TV, smartphone, swearable devices, laptops and other consumer electronics, the performance requirements of chip increases gradually. Power managerment chip supply high stability and high efficiency of electricity for other chips in the circuit system. It’s indispensability for the circuit system. Reference source is the indispensable function module of power management chip such as DC/DC converter, AC/DC converter, charging protection chip, LED Circuit, linear voltage regulator, PWM modulator. It provides reference voltage for other function modules in a system. So, the precision, stability and other performance of reference source will directly affect the performance of the chip. So the design of high performance reference source is particularly important. Low supply voltage, low temperature drift, high power supply rejection ratio, low power consumption are the current hot research topics of reference source. Bandgap reference source is the most mature and widely used topological structure of reference source. Therefore, this article will study the low temperature drift and high performance bandgap voltage reference.Starting with the bipolar transister, this paper introduces the principle of bandgap voltage reference. And this paper analyzes the Kuijk, Widlar, Brokaw and Banba conventional bandgap reference structure. Then the higher-order temperature characteristic and commonly used higher-order temperature compensation methods are studied. On the basis of the above, this paper proposes and designs a high performance bandgap reference which is based on the traditional Kuijk bandgap reference structure. The relationship between the bandgap reference power supply rejection ratio(PSRR) and the high-performance op-amp is studied. Then a dual-stage amplifier with high gain and high PSRR is designed. A piecewise curvature compensation method is proposed. The temperature characteristic of CTAT and PTAT voltage, and the sub-threshold characteristic of MOS are used to make curvature compensation for bandgap reference voltage at the low and high temperature.Based on the UMC 0.25μm BCD process model and HSPICE simulation bench, the bandgap reference circuit is verified by simulation. The simulation result shows that uncompensated temperature coefficient(TC) of reference voltage is 13.7ppm/℃ at-40℃-125℃, and the TC after compensation is 2.8ppm/℃. The PSRR is-91.2dB at low frequency. The line regulation(LNR) is 24.57μV/V. The low frequency loop gain is 64.6dB. and the phase margin is 83 degrees. The quiescent power dissipation current is 9.2μA.See from the simulation results, the TC obviously decrease after the reference voltage is compensated. In addition, the bandgap reference circuit in this paper has advantage on the performance of PSRR. LNR, power consumption, etc.