A retention circuit provided in a logic circuit enables power gating. The retention circuit includes a first terminal, a node, a capacitor, and first to third transistors. The first transistor controls electrical connection between the first terminal and an input terminal of the logic circuit. The second transistor controls electrical connection between an output terminal of the logic circuit and the node. The third transistor controls electrical connection between the node and the input terminal of the logic circuit. A gate of the first transistor is electrically connected to a gate of the second transistor. In a data retention period, the node becomes electrically floating. The voltage of the node is held by the capacitor.

A Low Voltage Differential Signaling (LVDS) transmitter includes driver circuit with a first transistor, a second transistor, a third transistor, a fourth transistor, a first resistor, and a second resistor. The first transistor is coupled between a first node and first output. The second transistor is coupled between the first node and a second output. The third transistor is coupled between the first output and a second node. The fourth transistor is coupled between the second output and the second node. The first resistor is coupled between the first output and a common mode node. The second resistor is coupled between the second output and the common mode node. A pre-driver circuit generates gate control signals controlling the first, second, third, and fourth transistors in response to a data signal. A controlled timing delay is applied to the timing of logic state transistors for the control signals.

A level shifter includes an input circuit having first and second input terminals configured to receive complementary input signals at a first voltage level and a second voltage level. A cross-latch circuit is coupled to the input circuit, and has first and second output terminals configured to provide complementary output signals at a third voltage level and a fourth voltage level. The input circuit includes first and second control nodes configured to output first and second control signals at the first voltage level and the fourth voltage level based on the input signals. A tracking circuit is coupled to the input circuit and the cross-latch circuit, and is configured to input first and second tracking signals to the cross-latch circuit based on the first and second control signals, wherein the first tracking signal is the greater of the first control signal and the third voltage level, and the second tracking signal is the greater of the second control signal and the third voltage level.

A capacitive-coupled level shifter includes a capacitive divider circuit having a first capacitive divider branch configured to couple a first input terminal to a first comparator terminal and a second capacitive divider branch configured to couple a second input terminal to a second comparator terminal. The first capacitive divider branch and the second capacitive divider branch are symmetric so as to cancel out a common mode voltage of a modulated signal input to the capacitive divider circuit. A level shifter system which includes the capacitive-coupled level shifter is also described.

An apparatus includes a differential input pair, a first resistor, a second resistor, and a comparator. The differential input pair having first and second differential inputs. The first differential input is adapted to be coupled to an output of a controller and the second differential input is adapted to be coupled to a signal ground of the controller. The first resistor is adapted to be coupled to a third resistor via the first differential input to form a first voltage divider. The second resistor is adapted to be coupled to a fourth resistor via the second differential input to form a second voltage divider. The comparator having first and second comparator inputs. The first comparator input is coupled between the first resistor and the first differential input. The second comparator input is coupled between the second resistor and the second differential input.

A circuit includes a current path and a negative bootstrap circuitry coupled to the current path. The current path is coupled between a floating voltage and a reference ground, and includes a current generator coupled through a resistor to the floating voltage at a first node of the current generator. The current generator is controlled by a pulse signal. The negative bootstrap circuitry includes a pump capacitor coupled to a second node of the current generator and to the reference ground. The pump capacitor is configured to provide a negative voltage at the second node of the current generator based on the pulse signal.

A level shifter includes an input circuit having first and second input terminals configured to receive complementary input signals at a first voltage level and a second voltage level. A cross-latch circuit is coupled to the input circuit, and has first and second output terminals configured to provide complementary output signals at a third voltage level and a fourth voltage level. The input circuit includes first and second control nodes configured to output first and second control signals at the first voltage level and the fourth voltage level based on the input signals. A tracking circuit is coupled to the input circuit and the cross-latch circuit, and is configured to input first and second tracking signals to the cross-latch circuit based on the first and second control signals, wherein the first tracking signal is the greater of the first control signal and the third voltage level, and the second tracking signal is the greater of the second control signal and the third voltage level.

An interface circuit may convert an input electrical signal at an input node in a first power domain having a first ground or reference voltage into an output electrical signal at an output node in a second power domain having a second ground or reference voltage. Notably, a level-shifting circuit in the interface circuit may selectively electrically couple to the input node and the output node. Then, when there is electrical coupling, the level-shifting circuit may perform level shifting between the first power domain and the second power domain. The level shifting may involve: passing, using a first filter, frequencies in the input electrical signal below a first corner frequency; passing, using a second filter in parallel with the first filter, frequencies in the input electrical signal above a second corner frequency; and combining outputs of the first filter and the second filter as the output electrical signal.

An apparatus includes a differential input pair, a first resistor, a second resistor, and a comparator. The differential input pair having first and second differential inputs. The first differential input is adapted to be coupled to an output of a controller and the second differential input is adapted to be coupled to a signal ground of the controller. The first resistor is adapted to be coupled to a third resistor via the first differential input to form a first voltage divider. The second resistor is adapted to be coupled to a fourth resistor via the second differential input to form a second voltage divider. The comparator having first and second comparator inputs. The first comparator input is coupled between the first resistor and the first differential input. The second comparator input is coupled between the second resistor and the second differential input.

A retention circuit provided in a logic circuit enables power gating. The retention circuit includes a first terminal, a node, a capacitor, and first to third transistors. The first transistor controls electrical connection between the first terminal and an input terminal of the logic circuit. The second transistor controls electrical connection between an output terminal of the logic circuit and the node. The third transistor controls electrical connection between the node and the input terminal of the logic circuit. A gate of the first transistor is electrically connected to a gate of the second transistor. In a data retention period, the node becomes electrically floating. The voltage of the node is held by the capacitor.