Patent ID: 8860709
Filing Date: 2014-10-14
Classification: H03K

Abstract:
1. A level converting circuit comprising: a level converting part configured to receive supply of a bias voltage and convert an input signal whose signal level is levels of a reference voltage and a first voltage to a signal level of a second voltage higher than the reference voltage and the first voltage; and a bias part configured to generate the bias voltage and supply the bias voltage to the level converting part, wherein the level converting part includes at least a first n-type field effect transistor, a second n-type field effect transistor, a third n-type field effect transistor, a fourth n-type field effect transistor, a first p-type field effect transistor, and a second p-type field effect transistor, a drain of the first n-type field effect transistor is connected to a drain of the first p-type field effect transistor and a gate of the second p-type field effect transistor, and the first n-type field effect transistor has a source connected to a drain of the third n-type field effect transistor and has a gate connected to a supply source of the bias voltage, a drain of the second n-type field effect transistor is connected to a drain of the second p-type field effect transistor and a gate of the first p-type field effect transistor, and the second n-type field effect transistor has a source connected to a drain of the fourth n-type field effect transistor and has a gate connected to the supply source of the bias voltage, a source of the first p-type field effect transistor and a source of the second p-type field effect transistor are connected to a second voltage source, a source of the third n-type field effect transistor and a source of the fourth n-type field effect transistor are connected to a reference voltage source, an input signal that takes a reference voltage level and a first voltage level in a complementary manner is supplied to a gate of the third n-type field effect transistor and a gate of the fourth n-type field effect transistor, the bias part includes a fifth n-type field effect transistor, a voltage drop part including at least one resistive element, and a current source having a power-supply-side terminal connected to a voltage source of a voltage higher than the first voltage, the fifth n-type field effect transistor has a source connected to a first voltage source and has a drain connected to one end of the resistive element, the other end of the resistive element is connected to a current supply terminal side of the current source, a gate of the fifth n-type field effect transistor is connected to a side of the other end of the resistive element, and the bias part generates the bias voltage higher than the first voltage by threshold voltage of the first n-type field effect transistor and the second n-type field effect transistor or the bias voltage that is higher than the first voltage and lower than the threshold voltage at a side of one end of the resistive element, and supplies the bias voltage to the gate of the first n-type field effect transistor and the gate of the second n-type field effect transistor in the level converting part.