Designing Bandgap Reference Circuit and Sub-Bandgap Reference Circuit with Low Temperature Coefficient

This paper presents low power Bandgap Reference and Sub-Bandgap Reference circuit with low temperature coefficient. PTAT, CTAT circuit and a startup circuit are required for designing a Bandgap Reference circuit. The PTAT and CTAT circuit comprises of BJT, OPAMP and resistor.Design of Bandgap and Sub-bandgap voltage reference circuit for low noise with low temperature coefficient is discussed in this paper. The performance of BGR depends on the type of Operational amplifier we are using. The supply voltage given to proposed BGR circuit is 3.3 V. And the supply voltage for Sub-Bandgap Reference circuit is 1.2V. 180nm CMOS technology is used for designing the proposed circuits. The BGR circuit generates a reference voltage in the range of 1.186V to 1.190V. And the Sub-BGR circuit generates voltage in the range of 0.560V to 0.561V. The minimum TC achieved for the BGR circuit is around 21ppm/°C and for sub-BGR it is 14ppm/°C in the temperature range of −40°C to 80°C. The output noise generated by the BGR circuit in this paper is equal to 45uV/sqrt (Hz) at 1Hz frequency and output noise of sub-BGR is 60uV/sqrt (Hz).