Producing flat supply voltage using a temperature-compensated BGR within LDO regulator loop

In this paper a flat supply voltage is produced for low-noise and low-jitter applications. A high gain two-stage amplifier, utilizing the indirect frequency compensation technique, is used to enhance the resolution of BGR loop. Then, the temperature-compensated BGR is used within the LDO loop to adjust the supply voltage around the desired value. A new start-up circuit is proposed to simply provide the initial conditions for BGR loop. Two-Stage amplifier provides more than 85dB DC-gain in all corners. The output voltage of the proposed BGR varies around 1250μv peak-to-peak voltage, when the temperature is increased from 0°C to 100°C. Also, LDO loop reduces the noisy supply from 5.5v±285mv to 5v±30mv, attenuating very high and also very low frequency noise harmonics, inside the LP filter and amplifier´s bandwidth, respectively. BGR loop is implemented in less than 0.06mm² active area in 0.5μm CMOS process.