Design of a Shot-voltage Safeguard Circuit without Reference Source

• 1、School of Integrated Circuits, Beijing University Of Posts and Telecommunications, 100876

Abstract：Undervoltage issues in power systems, caused by battery aging, load transients, or environmental disturbances, may lead to logic circuit failures, data loss, or hardware damage, thereby necessitating highly efficient undervoltage protection mechanisms. Conventional undervoltage protection circuits, which rely on bandgap references to establish reference voltages, suffer from structural complexity, excessive static power consumption, and high implementation costs, making them unsuitable for low-power applications. This paper proposes a reference-free undervoltage protection circuit design based on 0.35 μm BCD technology. By comparing two sampling voltages with distinct slopes for threshold detection, the proposed architecture eliminates the need for bandgap reference circuits while offering simplified circuitry, significantly reduced static power consumption, and excellent process compatibility. The design is particularly suited for cost-sensitive, low-power power management integrated circuits. Simulation results demonstrate that under a 20 V supply voltage, the circuit achieves a lockout threshold voltage of 12 V, a recovery threshold voltage of 12.54 V, and a hysteresis voltage interval of 0.54 V.

Keywords： Integrated Circuit Undervoltage Protection BCD Technology