Disclosed is an operation amplification circuit and an over-current protection method therefor. The operation amplification circuit comprises: a control unit, configured to generate an output control signal according to an input signal and an output signal; an output unit, configured to generate an output current under control of the output control signal, wherein the output unit comprises an output capacitor which is charged or discharged by the output current to generate the output signal; an over-current protection unit, obtaining a temperature control current according to an operating temperature of the operation amplification circuit, wherein when the operating temperature is greater than or equal to a predetermined temperature, the temperature control current is positively correlated with the operating temperature, and the over-current protection unit adjusts the output control signal according to the temperature control current to limit the output current.

Embodiments of a single event latch-up (SEL) protection circuit are provided, including: a first circuitry block coupled to a source of an input voltage a load, and digitally controlling a first switch; the first switch generates a load and senses an instantaneous load current iLoad. A second circuitry block is configured to generate an average iLoad and generate single event latch-up triggers (i.e., SEL fault detection) as a function of at least a comparison of the inst_iLoad and average iLoad; wherein this first circuitry block contains the analog based SET filtering needed to reduce false SEL triggers. A supervisor module generates on/off commands for the first switch, responsive to receiving the SEL detection in excess of a pre-programmed delay to provide the final SET filtering to prevent false SEL triggers. The first circuitry block removes the load voltage at N1 upon receiving an off command from the supervisor module.

An electrical safety system comprises a main safety device including a N-type transistor and an auxiliary safety device including a P-type transistor, alternately activated under command of a controller. The N-type transistor and the P-type transistor have the function of overcurrent protection, respectively in a first operating mode and in a second operating mode. The auxiliary safety device includes a passive component, connected in series with the P-type transistor, for providing a voltage drop when a current passes through the passive component, and a driving circuit for turning off the P-type transistor under control of the voltage drop exceeding a first threshold, in the second operating mode.

A wireline release tool for downhole intervention, the tool including a housing having an electrical input and an electrical output; a pass-through switch located inside the housing and electrically connected between the electrical input and the electrical output; and a circuit limiter device located inside the housing and electrically connected between the electrical input and the electrical output. The pass-through switch is connected in parallel to the circuit limiter device, between the electrical input and the electrical output.

Devices having one primary transistor, or a plurality of primary transistors in parallel, protect electrical circuits from overcurrent conditions. Optionally, the devices have only two terminals and require no auxiliary power to operate. In those devices, the voltage drop across the device provides the electrical energy to power the device. A third or fourth terminal can appear in further devices, allowing additional overcurrent and overvoltage monitoring opportunities. Autocatalytic voltage conversion allows certain devices to rapidly limit or block nascent overcurrents.

A protective circuit (301) and a display drive device. The protective circuit (301) comprises: when an electrical overstress problem occurs in a logic signal, the voltage of an output end of a controlled switch circuit (100) is greater than a first preset voltage, so that a voltage threshold circuit (101) is turned on, and the controlled switch circuit (100) turns off an input end and the output end thereof, thereby preventing electrical overstress from affecting a driver chip (300) and causing damage to the driver chip (300). Moreover, the voltage potential of a controlled end of the controlled switch circuit (100) is clamped by means of a voltage clamp circuit (102) to stabilize the operating characteristics of the controlled switch circuit (100).

Provided is a circuit structure for suppressing surge current, which includes a surge current suppression judgment circuit, a switching control circuit and a self-boosting regulating circuit. An output end of the surge current suppression judgment circuit is connected with the switching control circuit. An output end of the switching control circuit is connected with the self-boosting regulating circuit. The switching control circuit and the self-boosting regulating circuit are both connected with a current input end Vin. An output end of the self-boosting regulating circuit is connected with an input end of the surge current suppression judgment circuit. The output end of the self-boosting regulating circuit is an output end Vout of the whole circuit structure for suppressing surge current.

A method for reducing a thermal load on a switching element of an electronic fuse when switching on a load, wherein (a) a switching element is activated, (b) the switching element is deactivated and (c) the switching element is re-activated after reaching a set value of a switch-off duration, where steps (b) and (c) are repeated until an output voltage reaches a value that falls below a specified difference with respect to an input voltage of an electronic fuse or an output current reaches a specified duration current, where set values of a switch-on duration and/or switch-off current and the switch-off duration are maintained until new set values have been determined based on the output voltage, output current, and/or temperature, a pulse duty factor between the switch-on duration and the switch-off duration is adapted, and the specified maximum allowable temperature increase of the switching element is further observed.

The present disclosure provides a control method for a current-limiting control circuit and an electrical system. The current-limiting control circuit includes a high voltage side connected with a direct-current (DC) bus, a low voltage side connected with a load, and a regulating unit connected with the high voltage side and the low voltage side, the regulating unit including at least one MOS transistor, and the control method includes: detecting current I.sub.0 of the current-limiting control circuit; determining whether the current I.sub.0 is greater than a preset current I; and determining that the current-limiting control circuit has a short circuit fault, and entering a current limiting control mode to limit a persistent growth of the current, in a case where the current I.sub.0 is greater than the preset current I.

Methods and apparatuses for protecting a low voltage (LV) circuit implemented with LV transistors are presented. Protection is provided via a protection circuit operating in a high voltage domain defined by a varying supply voltage and a reference ground. The protection circuit generates high side, V.sub.H, and low side, V.sub.L, voltages to the LV circuit, while protecting the LV circuits from high voltage and maintaining a minimum difference voltage, V.sub.H−V.sub.L. The protection circuit generates the difference voltage based on a voltage across a resistor of a resistor ladder that is coupled between the varying supply voltage and the reference ground. The protection circuit includes a clamp circuit that limits the minimum difference voltage for low values of the supply voltage. The protection circuit generates the difference voltage according to a nonlinear transfer function of the supply voltage that includes two linear segments having different slopes and a nonlinear segment that provides a continuous and smooth transition between the two linear segments.