A charge pump circuit includes a first pump unit and a second pump unit. The first pump unit includes a first capacitor and a first transistor, and generates a first node voltage by using a clock signal. The second pump unit includes a second capacitor, a second transistor, and a third transistor, and generates a negative output voltage by using the first node voltage. The clock signal and the first node voltage are each toggled between a low-level voltage and a high-level voltage. A magnitude of an absolute value of the negative output voltage is greater than a magnitude of an absolute value of the high-level voltage of the clock signal. A body of the third transistor is electrically isolated from a body of the second transistor.