Offset cancellation in bandgap references with CMOS operational amplifiers

Two architectures of a bandgap reference with CMOS operational amplifiers are investigated, implemented and compared. In order to reduce the dependence of the reference voltage with temperature and power supply, the trimming technique is often used. We propose a new method of lowering the reference voltage variation, based on a very low offset voltage amplifier. Two operational amplifier schematics are designed, simulated and measured.