Design of current bandgap startup circuit with dynamic threshold control

This paper proposes a novel startup circuit for a current-mode bandgap reference (CMBGR) to resolve startup issues in low-voltage CMOS processes while balancing design cost, PVT (process, voltage, temperature) robustness, CMBGR performance, and curvature compensation compatibility. The proposed circuit employs a dynamic threshold voltage mechanism, implemented in 0.11 μm CMOS technology, which dynamically adjusts the startup threshold to ensure reliable operation across varying PVT conditions. Validation through 20400 Monte Carlo simulations under diverse PVT settings confirmed successful startup without failure. The CMBGR operates over a supply voltage range from 2.3 V to 4.3 V, delivering a configurable reference voltage output from 0.1 V to 2.0 V. A temperature coefficient of 8.7×10^-6/℃ was achieved, which is superior to current 41.5×10^-6/℃ and maintains the inherently low-temperature sensitivity of the CMBGR. Moreover, the design preserves full compatibility with curvature compensation strategies and requires no additional circuitry or performance trade-offs. This approach provides a comprehensive and efficient solution for achieving stable startup in configurable CMBGR applications.