A Fully Integrated Low Noise and High Accuracy Low-Dropout Regulator in 130nm SiGe BiCMOS

In this work, a method for obtaining an LDO with low output noise is proposed by applying a bandgap reference source that does not contain an operational amplifier and uses all triodes. In the bandgap reference source, an additional loop is used to achieve the effect of clamping the voltage. In the core circuit, a buffer and a pole tracking circuit are used to achieve a balance between high loop gain, stability and load transient response. An off-chip capacitor-free LDO is designed using the proposed methodology with SiGe 130 nm BiCMOS process. The design has a noise of 1.16 µV at 10 Hz and an integrated noise of 23.7 µV rms over the frequency range of 10 Hz ~ 100 MHz. The LDO has a small output capacitance of 20 pF and a quiescent current of only 400 µA.