4.6 A 0.8V, 31ppm/°C, −40dB DC-to-GHz Power-Supply-Rejection Standard-Vth Core-MOS-Only Voltage Reference with a 294µm2Area

PVT-independent voltage references (VRs) are critical analog blocks for data converters and sensors in system-on-chips $(\text{SoCs})$. As advanced technology nodes continue to scale down, the demand for core-device-only reference circuits that can operate at core-domain supply voltages $(\mathrm{V}_{\text{DD}}\mathrm{S})$ is becoming increasingly important for area-shrinkage and reliability considerations. Working at sub-1V $\mathrm{V}_{\text{DD}}$ is a significant design barrier for BJT-based VRs due to the headroom limitation of the emitter-base junction voltage $(\mathrm{V}_{\text{EB}})$ of BJTs and the drain-source saturation voltage of the current sources. Reference [1] presents a $0 7\mathrm{V}$ BJT-based VR using deep-n-well (DNW) base-structure PNP devices with lower $\mathrm{V}_{\text{EB}}$ requirements, but DNWs usually are not compatible with a standard logic CMOS process. Charge-pump [2] and switched-capacitor [3] techniques can reduce the supply of BJT-based reference circuits to $0 5\mathrm{V}$ to $0 85\mathrm{V}$. However, switching-mode VRs typically require large filters to remove output ripples, which results in an extra area penalty.