Patent ID: 9438239
Filing Date: 2016-09-06
CPC Classification: H02M,H03K

Claim Text:
1. A level shifter comprising: a first cascode portion, including a first transistor of a first conductivity type and a second transistor of a second conductivity type which are cascode-coupled to each other, configured to transmit a first input signal; a second cascode portion, including a third transistor of the first conductivity type and a fourth transistor of the second conductivity type which are cascode-coupled to each other, configured to transmit a second input signal which is in a complementary relation with the first input signal; a latch portion configured to retain a first output signal and a second output signal obtained by changing, based on a first voltage obtained by boosting a power supply voltage, potential levels of the first input signal and the second input signal; and a potential-difference suppression circuit, coupled in parallel to the first cascode portion, configured to control a potential difference between a source and a drain of each of the first transistor and the second transistor, wherein a drain of the first transistor is coupled to a drain of the second transistor at a first node, and the potential-difference suppression circuit includes a first protection element and a second protection element having one terminal coupled to one terminal of the first protection element at a second node which is coupled to the first node.