An electronic circuit includes an electronic device, an input/output terminal, and a protection device. The electronic device includes a signal terminal to receive an input signal. The input/output terminal is configured to receive the input signal from a source external to the electronic circuit. The protection device is coupled to the electronic device and to the input/output terminal. The protection device is configured to protect the electronic device from voltage of the input signal exceeding a threshold. The protection device includes a first semiconductor region, a first contact, and a second contact. The first contact connects the first semiconductor region to the input/output terminal. The second contact connects the first semiconductor region to the signal terminal of the electronic device.