Shanghai Huali Microelectronics Corporation

Shanghai Huali Integrated Circuit Corporation

Yu Jia

Yifei Qian

The present application discloses a multi-level voltage detector circuit. The voltage dividing circuit includes a first resistor string and a second circuit. The first resistor string is formed by n+1 voltage dividing resistors connected in series and outputs n divisional voltages. The second circuit provides n lower voltage dividing resistors. A kth lower voltage dividing resistor detects kth rise and fall detection points of a power supply voltage. When the kth rise detection point is detected, the second circuit provides a kth lower voltage dividing resistor and short-circuits the kth lower voltage dividing resistor. When the kth fall detection point is detected, the second circuit provides the kth lower voltage dividing resistor to a position between a second end of an nth voltage dividing resistor and the ground. As the value of k increases, the resistance of the kth lower voltage dividing resistor decreases.

Multilevel voltage detector circuit

The present application discloses a power-on-reset circuit, which optimizes a hysteresis circuit and a reset signal generation circuit, and introduces a seventh PMOS transistor as a switch transistor to achieve the differentiation of control voltages at a gate end of a first NMOS transistor during powering-on and off. A voltage rise detection point is determined by a partial voltage of a resistor during powering-on, while a voltage fall detection point is directly determined by a power supply voltage during powering-off. Such differentiation may achieve a significant separation between the voltage rise detection point and the voltage fall detection point, reducing the voltage fall detection point to near a threshold voltage of the first NMOS transistor, and meeting the demand for a lower voltage fall detection point, which is consistent with a practical application of the power-on-reset circuit in an MCU.

Growing community of inventors

Shanghai, China

Yu Jia