This letter presents a novel under-voltage and over-voltage (UVOV) detection circuit which detects whether the supply voltage is within the operating range or not, with a simple configuration. The proposed circuit exploits only a transistor for detecting both under and over supply voltages and hence, it provides smaller area and better robustness to offset and mismatch compared to the previous ones. The prototype is implemented in 5um BCDMOS process with an active area of 0.0625mm². The measurement results show that the prototype detects under and over voltages at 3.85V with 650mV of hysteresis and 48.45V with 700mV of hysteresis, respectively, while dissipating 18.7uA at 12V in simulation.