A Wide Temperature Range Dual-Temperature Protection Rail-to-Rail Operational Amplifier System Based on HV-to-LV LDO

Based on a 0.18 μm BCD process, this paper presents a high-performance rail-to-rail operational amplifier power management and control system for high-voltage applications, which can be widely applied to fields such as photoelectric conversion, automotive electronics, and industrial control. The design integrates a High-voltage-to-low-voltage low-dropout linear regulator (HV-to-LV LDO), a high-precision rail-to-rail operational amplifier, and an Over-Temperature and Under-Temperature Protection module (OT/UT Protection). Aiming at the issues of insufficient high-voltage compatibility and passive thermal management in traditional solutions, technical breakthroughs are achieved through the design of the HV-to-LV LDO and OT/UT Protection module. The LDO employs high-voltage-tolerant devices and a current-mirror clamping structure. Simulation results show that within a wide input voltage range of 5 V–40 V, the HV-to-LV LDO stably outputs 3.3 V with a temperature drift coefficient below 6 ppm/°C across the entire input voltage range. The system achieves a fast start-up time of 9.6 μs over the temperature range of −40°C to 125°C. Under the 3.3 V power supply provided by the high-voltage-to-low-voltage LDO, the rail-to-rail operational amplifier realizes rail-to-rail output with a load capacity of 50mA, a voltage gain exceeding 120dB, a unity-gain bandwidth (GBW) greater than 10MHz, a power supply rejection ratio (PSRR) of 174.37dB, and a common-mode rejection ratio (CMRR) of 126.58dB. Thermal reliability is enhanced through the integration of the OT/UT Protection module.