Abstract: A radiation-hardened charge pump has been proposed in which a novel numerical control restrain (NCR) circuit is applied to reduce the current perturbation and the clock jitter caused by the single energetic particle strikes. A hardened charge pump is implemented in a self-biased PLL with 130 nm CMOS process to verify the circuit and the corresponding results show that the peak of current perturbation reduces by up to 60% and the frequency stability reduces to 8e-4 compared with the traditional CP at the same time of current perturbation.