A level shifter includes a buffer circuit, a first shift circuit, and a second shift circuit. The buffer circuit provides a first signal and a first inverted signal to the first shift circuit, such that the first shift circuit provides a second signal and a second inverted signal to the second shift circuit. The second shift circuit generates a plurality of output signals according to the second signal and the second inverted signal. The first shift circuit includes a plurality of first stacking transistors and a first voltage divider circuit. The first voltage divider circuit is electrically coupled between a first system high voltage terminal and a system low voltage terminal. The first voltage divider circuit is configured to provide a first inner bias to gate terminals of the first stacking transistors.

A level shifter circuit is provided. In some examples, the level shifter circuit includes a first set of transistors and a second set of transistors coupled between first and second power supply nodes. The control terminals of the first and second lower transistors are coupled to an input node. The level shifter circuit also includes a third set of transistors and a fourth set of transistors coupled between first and third power supply nodes. A control terminal of a third lower transistor is coupled to a second intermediate node, and a control terminal of a fourth lower transistor is coupled to a first intermediate node. Control terminals of the first upper transistor and the fourth upper transistor are coupled to a third intermediate node. Control terminals of the second upper transistor and the third upper transistor are coupled to a fourth intermediate node.

Some embodiments provide a voltage-level shifter circuit comprising a cross-coupled transistor pull-up network that includes a plurality of diode-connected transistors configured to cause the state of the cross-coupled transistor network to switch at a low current through a pull-down network coupled thereto, such as a current corresponding to near-threshold voltage or sub-threshold voltage operation of the pull-down network.

Some embodiments provide a voltage-level shifter circuit comprising a cross-coupled transistor pull-up network that includes a plurality of diode-connected transistors configured to cause the state of the cross-coupled transistor network to switch at a low current through a pull-down network coupled thereto, such as a current corresponding to near-threshold voltage or sub-threshold voltage operation of the pull-down network.

A level converting enable latch includes a level shifter circuit and a latch circuit. The level shifter circuit receives a first data input signal, and generates a first data output signal, wherein the first data input signal and the first data output signal have different voltage swings. The latch circuit sets a second data output signal in response to the first data output signal when a latch enable signal is set to a first logic value, and latches the second data output signal when the latch enable signal is set to a second logic value. The latch circuit includes a first control circuit. The first control circuit enables a latch feedback loop of the latch circuit when the latch enable signal is set to the second logic value, and disables the latch feedback loop of the latch circuit when the latch enable signal is set to the first logic value.

A level shifter circuit to convert a first signal having an input voltage range V1 to a level shifted output having an output voltage range V2 includes an NMOS depletion mode transistor having a drain terminal connected to an output range upper-level supply node, a source connected to an intermediate node and a gate connected to an output node, a PMOS enhancement mode transistor having a drain terminal connected to the output node, a source connected to the intermediate node and a gate connected to an input node, and an NMOS enhancement mode transistor having a drain terminal connected to the output node, a source connected to an output range lower-level supply node and a gate connected to the input node.

A level shifter includes a pre-level shifter and a selector. The selector is coupled to the pre-level shifter. The pre-level shifter shifts an input digital voltage to a first digital voltage and a second digital voltage. The levels of the first digital voltage and the second digital voltage transition sequentially in time when the level of the input digital voltage transitions from one logic to the other. The selector selects and outputs the first digital voltage whose level transitions earlier in time compared to the transition of the level of the second digital voltage.

A level shifter includes a buffer circuit, a first shift circuit, and a second shift circuit. The buffer circuit provides a first signal and a first inverted signal to the first shift circuit, such that the first shift circuit provides a second signal and a second inverted signal to the second shift circuit. The second shift circuit generates a plurality of output signals according to the second signal and the second inverted signal. The first shift circuit includes a plurality of first stacking transistors and a first voltage divider circuit. The first voltage divider circuit is electrically coupled between a first system high voltage terminal and a system low voltage terminal. The first voltage divider circuit is configured to provide a first inner bias to gate terminals of the first stacking transistors.

A low leakage level shifter circuit converts a lower voltage signal to a higher voltage signal. The level shifter includes a half-latch with an output node that is toggled between the higher voltage and a reference voltage based on an input signal toggled between the lower voltage and the reference voltage. Crosscoupled transistors keep one of the output node and a complement node charged to the higher voltage by a charge transistor while the other node is discharged by a discharge transistor. To discharge the charged node, current through the discharge transistor needs to be higher than current through the charge transistor, but the discharge transistor is only partially turned on by the lower voltage input signal. First and second resistors coupled between the charge transistors and a voltage source reduce current through the charge transistors, allowing the discharge transistors to be smaller to avoid a high leakage current.

An improved cross-coupled voltage level shifter is disclosed that is capable of achieving substantially higher data transfer speeds with reduced transistor sizes than existing cross-coupled voltage level shifters. The voltage level shifter includes a cross-coupled latch, control circuitry that initiates a state transition of the latch responsive to activation, where the control circuitry is activated by a change in a logic voltage level of an input signal to the voltage level shifter, and feedback circuitry that reinforces the latch action of the cross-coupled latch. The control circuitry may include pull-down transistors that are thin-gate devices, and thus, substantially smaller in area than what would otherwise be needed to meet the large current requirement of the pull-down transistors as compared to latch transistors of the latch.