An integrated circuit includes an input pad and a Schmitt trigger coupled to the input pad. The Schmitt trigger includes a main PMOS branch that charges an intermediate node of the Schmitt trigger responsive to voltage transitions at the input node. The Schmitt trigger includes a charging assistance circuit that helps to rapidly charge the intermediate node of the Schmitt trigger. The charging assistance circuit includes a parallel PMOS branch in parallel with the main PMOS branch.

The disclosure relates to laboratory equipment with flammable refrigerant and connected to at least two different electrical potentials for supplying the equipment with electrical energy. An electrical switch arrangement has first and second switches for electrical separation from, respectively, the first and second potentials. A sequence controller switches on the first switch and thereafter the second switch. A monitoring device is connected via a first contact on the equipment side to the first switch and via a second contact on the mains side to an electrical potential other than the first electrical potential for detecting a switched-on state of the first switch and signaling the detection to the sequence controller. When the monitoring device signals a switched-on state, the sequence controller blocks operation of the equipment as a function of the signaled switched-on state and whether the first switch is expected to be switched on or switched off.

The disclosure relates to laboratory equipment with flammable refrigerant and connected to at least two different electrical potentials for supplying the equipment with electrical energy. An electrical switch arrangement has first and second switches for electrical separation from, respectively, the first and second potentials. A sequence controller switches on the first switch and thereafter the second switch. A monitoring device is connected via a first contact on the equipment side to the first switch and via a second contact on the mains side to an electrical potential other than the first electrical potential for detecting a switched-on state of the first switch and signaling the detection to the sequence controller. When the monitoring device signals a switched-on state, the sequence controller blocks operation of the equipment as a function of the signaled switched-on state and whether the first switch is expected to be switched on or switched off.

The present invention provides a Schmitt trigger circuit in which chattering does not occur in the output of the Schmitt trigger circuit even when it is connected to a communication bus without impedance matching and reflected noise is superimposed on the input signal. The Schmitt trigger circuit includes: a first signal detection circuit; a second signal detection circuit; a latch circuit; a selection signal generation circuit; a first input port; and a first output port. The first signal detection circuit is connected to the first input port, the latch circuit and the selection signal generation circuit. The second signal detection circuit is connected to the first input port, the latch circuit and the selection signal generation circuit. The latch circuit is connected to the selection signal generation circuit and the output port. The selection signal generation circuit includes a delay circuit.

A circuit for comparing a voltage with a threshold, including: first and second nodes of application of the voltage; a first branch including a first transistor series-connected with a first resistor between first and second nodes; a second branch parallel to the first branch, including second and third series-connected resistors forming a voltage dividing bridge between the first and second nodes, the midpoint of the dividing bridge being connected to a control node of the first transistor; and a third branch including a second transistor in series with a resistive and/or capacitive element, between the control node of the first transistor and the first or second node, a control node of the second transistor being connected to the junction point of the first transistor and of the first resistor.

A circuit for comparing a voltage with a threshold, including: first and second nodes of application of the voltage; a first branch including a first transistor series-connected with a first resistor between first and second nodes; a second branch parallel to the first branch, including second and third series-connected resistors forming a voltage dividing bridge between the first and second nodes, the midpoint of the dividing bridge being connected to a control node of the first transistor; and a third branch including a second transistor in series with a resistive and/or capacitive element, between the control node of the first transistor and the first or second node, a control node of the second transistor being connected to the junction point of the first transistor and of the first resistor.

A circuit includes an inverter coupled between an input and an output. The inverter includes first and second pull-down transistors having control terminals coupled to the input, a pull-up resistor, and a pull-up transistor having a control terminal coupled to the input. The first and second pull-down transistors are coupled in series along a pull-down path extending between a first voltage supply terminal and the output. The pull-up resistor and pull-up transistor are coupled in series along a pull-up path extending between a second voltage supply terminal and the output. A hysteresis transistor has a control terminal coupled to the output. The hysteresis transistor is coupled to the inverter along a hysteresis path extending between the first voltage supply terminal and the pull-up path. A clamp circuit is coupled to the inverter along a clamp path extending between the first voltage supply terminal and the pull-down path.

A circuit includes an inverter coupled between an input and an output. The inverter includes first and second pull-down transistors having control terminals coupled to the input, a pull-up resistor, and a pull-up transistor having a control terminal coupled to the input. The first and second pull-down transistors are coupled in series along a pull-down path extending between a first voltage supply terminal and the output. The pull-up resistor and pull-up transistor are coupled in series along a pull-up path extending between a second voltage supply terminal and the output. A hysteresis transistor has a control terminal coupled to the output. The hysteresis transistor is coupled to the inverter along a hysteresis path extending between the first voltage supply terminal and the pull-up path. A clamp circuit is coupled to the inverter along a clamp path extending between the first voltage supply terminal and the pull-down path.

A circuit includes an inverter coupled between an input and an output. The inverter includes first and second pull-down transistors having control terminals coupled to the input, a pull-up resistor, and a pull-up transistor having a control terminal coupled to the input. The first and second pull-down transistors are coupled in series along a pull-down path extending between a first voltage supply terminal and the output. The pull-up resistor and pull-up transistor are coupled in series along a pull-up path extending between a second voltage supply terminal and the output. A hysteresis transistor has a control terminal coupled to the output. The hysteresis transistor is coupled to the inverter along a hysteresis path extending between the first voltage supply terminal and the pull-up path. A clamp circuit is coupled to the inverter along a clamp path extending between the first voltage supply terminal and the pull-down path.

A circuit includes an inverter coupled between an input and an output. The inverter includes first and second pull-down transistors having control terminals coupled to the input, a pull-up resistor, and a pull-up transistor having a control terminal coupled to the input. The first and second pull-down transistors are coupled in series along a pull-down path extending between a first voltage supply terminal and the output. The pull-up resistor and pull-up transistor are coupled in series along a pull-up path extending between a second voltage supply terminal and the output. A hysteresis transistor has a control terminal coupled to the output. The hysteresis transistor is coupled to the inverter along a hysteresis path extending between the first voltage supply terminal and the pull-up path. A clamp circuit is coupled to the inverter along a clamp path extending between the first voltage supply terminal and the pull-down path.