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 single stage transmitter that operates at high speed is configured to operate as a driver in write mode and a termination in read mode. The driver configuration includes two circuits. The first circuit includes a PMOS cross-coupled device and a PMOS cascode circuit. The second circuit includes a NMOS cross-coupled device and a NMOS cascode circuit. The PMOS cross-coupled device and the NMOS cross-coupled device is connected in series by alternating current (AC) coupling capacitors. The termination configuration includes a third circuit including MOSFET transmission gates and an inverter controlled by a termination mode enable signal. In write mode, the third circuit of the single stage transmitter is turned off and the first and second circuits are operational. In read mode, the first and second circuits of the single stage transmitter are inactive and the third circuit is operational.

Disclosed is a semiconductor integrated circuit comprising a master chip including a first buffer circuit coupled to a first power line that is supplied with a first voltage and a first supply circuit that supplies a second voltage, having a lower voltage level than the first voltage, to a first through line in response to a control signal, and a slave chip, coupled to the first through line, including a second buffer circuit coupled to a second power line supplied with the second voltage and a second supply circuit that supplies the second voltage to a second through line in response to the control signal, which indicates whether the master chip and the slave chip are stacked.

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.

Power supply circuit having low quiescent current for a bypass mode. One example power supply circuit generally includes a transistor; a switching node coupled to a source of the transistor; a power supply rail; a capacitor having a first terminal coupled to the power supply rail and having a second terminal coupled to the switching node; a gate driver having an output coupled to a gate of the transistor, having a first power input coupled to the power supply rail, and having a second power input coupled to the switching node; logic having a first input coupled to the first terminal of the capacitor, having a second input coupled to the second terminal of the capacitor, and having a first output; and a pullup circuit having a control input coupled to a second output of the logic and having an output coupled to the gate of the transistor.

Disclosed herein are silicon-on-insulator (SOI) switches and associated control circuits having level shifters configured to provide increased voltages (positive and/or negative) to the switches. The disclosed level shifters can be configured to provide increased voltages and can be used with high-linearity switches and/or can improve the linearity of switches. The improved switch performance can improve front end module performance for applications such as carrier aggregation (CA) and multiple input multiple output (MIMO) as well as with protocols such as Long-Term Evolution Advanced (or LTE-A).

A semiconductor device includes a substrate having PMOSFET and NMOSFET regions spaced apart from each other in a direction, a device isolation layer provided on the substrate that defines first and second active patterns respectively on the PMOSFET and NMOSFET regions, a gate electrode crossing the first and second active patterns, first and second source/drain patterns respectively provided on the first and second active patterns respectively and near the gate electrode, and an active contact extending in the direction and coupled to the first and second source/drain patterns. The active contact includes first and second body portions, which are respectively provided on the first and the second source/drain patterns, and a first protruding portion and a recessed portion, which are provided between the first and second body portions and on the device isolation layer between the PMOSFET and NMOSFET regions. The recessed portion has an upwardly recessed bottom.

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.

Systems and methods for frequency reference generation are described. In an embodiment, a frequency reference circuit, includes: a bandgap proportional to temperature (PTAT) generator circuit that generates a bandgap PTAT current; a resistor complementary to temperature (CTAT) generator circuit that generates a resistor CTAT current; an adder that adds the PTAT current and the CTAT current to generate a constant current I.sub.cons; a switched-resistor (switched-R) circuit that receives the constant current I.sub.cons and a previously generated output clock and generates an output; a bandgap voltage reference generator circuit that generates a bandgap voltage V.sub.BG; an integrator circuit that receives the output of the switched-R circuit and the bandgap voltage V.sub.BG and generates an output; and a voltage-controlled oscillator (VCO) circuit that receives the output of the integrator circuit and generates a frequency reference.

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.