US 8,570,091 B2 · Level shifter

Abstract

A level shifter, converting an input signal into an output signal for level shifting, including a leakage blocking circuit having cascaded P-channel transistors and one N-channel transistor. The P-channel transistor at a beginning stage provides a gate for receiving the input signal and a source coupled to a gate of the P-channel transistor at a secondary stage. At intermediate stages, each P-channel transistor provides a source coupled to a gate of the subsequently cascaded P-channel transistor. At a final stage, the P-channel transistor provides a source coupled to a voltage source and a drain coupled to an output terminal of the leakage blocking circuit for the outputting of the output signal. The N-channel transistor has a gate which is coupled to receive the input signal as well, a source coupled to a common voltage, and a drain coupled to the output terminal of the leakage blocking circuit.

Claims18

Dependent claims

A level shifter converting an input signal to be within a range of a first voltage range into an output signal to be within a range of a second voltage range, comprising:

a leakage blocking circuit, having an input terminal coupled to receive the input signal and an output terminal coupled to provide the output signal, comprising:
a plurality of first-type-channel transistors that are cascaded, wherein the first-type-channel transistor at a beginning stage has a gate which is coupled to receive the input signal and a source directly connected to a gate of the first-type-channel transistor at a secondary stage, and, at each intermediate stage, each first-type-channel transistor has a source directly connected to a gate of a subsequently cascaded first-type-channel transistor, and, the first-type-channel transistor at a final stage has a source coupled to a voltage source and a drain coupled to the output terminal of the leakage blocking circuit;
and
a second-type-channel transistor, having a gate which is coupled to receive the input signal, a source coupled to a common voltage, and a drain coupled to the output terminal of the leakage current block circuit,
wherein every one of the first-type-channel transistors except for the one at the final stage has a drain directly connected to the common voltage.

2 more elements

Dependencies are inferred from the claim text.

Level shifter

Life of this patent

Level shifter

Life of this patent

Abstract

Claims18