ACCURATE LOW-POWER BANDGAP VOLTAGE REFERENCE IN 0.5 MU-M CMOS TECHNOLOGY

In mixed level applications, accurate voltage references are difficult to realise due to the lack of lateral pnps and the large offsets inhe rent to CMOS opamps. If low power is essential, the accuracy is mainly impaired by the increased offset of the opamps. It is shown that by u sing chopping techniques, the accuracy of a bandgap voltage reference can be improved by about ten times without laser trimming, with the ad ded benefit of reducing the 1/f noise of the amplifier.