A power semiconductor circuit is provided for clamping the voltage across the circuit when a power semiconductor switch is opened (i.e., turned off). The circuit may include a first surge arrester and a first semiconductor switch coupled in parallel with the power semiconductor switch. The first semiconductor switch is coupled in series with the first surge arrester. A second surge arrester may be coupled to the gate of the first semiconductor switch to control current flow through the first semiconductor switch and the first surge arrester.

A driver circuit controls an output unit that switches whether or not to supply a current to an output line, in accordance with a potential difference between a first control signal to be input and a voltage of the output line. The driver circuit has a control line transmitting the first control signal to the output unit; a connection switching unit switching whether or not to connect the control line and the output line; a pre-stage control unit that is provided between a high potential line and a low potential line and selects and outputs a potential of any one of the high potential line and the low potential line in accordance with a second control signal; and a post-stage control unit causing the connection switching unit to connect the control line and the output line when the pre-stage control unit outputs a voltage higher than a predetermined threshold value.

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 drive circuit drives a power semiconductor element including a gate electrode, a first main electrode and a second main electrode. The drive circuit includes: a controller to control an opened/closed state of the power semiconductor element based on an externally received command; a short circuit determination circuitry to determine whether the power semiconductor element is in a short-circuited state in a turn-on operation of the power semiconductor element, and output a determination signal indicating a determination result; and a filter to receive the determination signal from the short circuit determination circuitry, generate a delay signal of the determination signal, and output the delay signal to the controller. A delay time of the filter is set to be longer than a length of a Miller period in the turn-on operation of the power semiconductor element.

A drive circuit drives a power semiconductor element including a gate electrode, a first main electrode and a second main electrode. The drive circuit includes: a controller to control an opened/closed state of the power semiconductor element based on an externally received command; a short circuit determination circuitry to determine whether the power semiconductor element is in a short-circuited state in a turn-on operation of the power semiconductor element, and output a determination signal indicating a determination result; and a filter to receive the determination signal from the short circuit determination circuitry, generate a delay signal of the determination signal, and output the delay signal to the controller. A delay time of the filter is set to be longer than a length of a Miller period in the turn-on operation of the power semiconductor element.

A current sense circuit includes channels a detection terminal, a feedback circuit and third-type switches. The channels respectively have first-type switches and second-type switches. Each of the first-type switches supplies an electric power to a load when the first-type switch is turned on. The second-type switches are respectively connected to the first-type switches in parallel, and respectively detect currents flowing through the first-type switches. The detection terminal is connected to the second-type switches. The feedback circuit includes a single operational amplifier having a first input terminal and a second input terminal. The first input terminal is connected to respective electrodes of the first-type switches close to the load. The second input terminal is connected to respective electrodes of the second-type switches close to the detection terminal. The third-type switches are connected to the electrodes of the first-type switches and the first input terminal.

Examples described herein provide an apparatus having a circuit with a grounding circuit and a switch. The apparatus generally includes a gate induced drain leakage (GIDL) protection circuit coupled to the switch and to an output voltage. The GIDL protection circuit may include a switch protection circuit configured to maintain a drain voltage of the switch less than a first supply voltage (V.sub.dd) when the circuit is in an OFF state; and a ground protection circuit configured to maintain a drain voltage of the grounding circuit less than the first supply voltage when the circuit is in an ON state.

Examples described herein provide an apparatus having a circuit with a grounding circuit and a switch. The apparatus generally includes a gate induced drain leakage (GIDL) protection circuit coupled to the switch and to an output voltage. The GIDL protection circuit may include a switch protection circuit configured to maintain a drain voltage of the switch less than a first supply voltage (V.sub.dd) when the circuit is in an OFF state; and a ground protection circuit configured to maintain a drain voltage of the grounding circuit less than the first supply voltage when the circuit is in an ON state.

A switch device for switching an analog electrical input signal includes: a switching transistor being a flipped-well-silicon-on-insulator-NMOS transistor; and a bootstrapping arrangement including a voltage providing arrangement for providing a floating voltage during the on-state, wherein the floating voltage is provided at a positive terminal and at a negative terminal of the voltage providing arrangement; wherein the bootstrapping arrangement is configured in such way that during the on-state the positive terminal is electrically connected to the front gate contact of the switching transistor and to the back gate contact of the switching transistor, and the negative terminal is electrically connected to the source contact of the switching transistor; wherein the bootstrapping arrangement is configured in such way that during the off-state the positive terminal and the negative terminal are not electrically connected to the switching transistor.

A surgical retractor assembly for providing surgical exposure. The surgical retractor assembly consists of multiple ring segments connected by adjustable ratchet mechanisms to form a complete ring. The ratchet mechanisms are attached to tissue retractor blades which provide exposure of the wound when expanded, without the requirement of a direct connection/attachment to an operating table. The tissue retractor blades are attached in a manner which is adjustable and facilitates the ability of the overall surgical retractor assembly (ring segments and connectors) to be raised or lowered with respect to the patient. The ring segments also allow attachments of additional retractor blades or other surgical retractor accessories for additional surgical exposure.