A power-on reset circuit with reduced detection time. One example power-on reset circuit generally includes a voltage sensing circuit having an input coupled to a first power supply rail; a variable resistance component having a control input coupled to an output of the voltage sensing circuit and having a first terminal coupled to the first power supply rail; and an amplitude detection circuit having a first input coupled to the first power supply rail and having a second input coupled to a second terminal of the variable resistance component, the amplitude detection circuit being configured to generate a power-on reset signal at an output of the amplitude detection circuit based on a difference between a first voltage of the first power supply rail and a second voltage at the second terminal of the variable resistance component.

A semiconductor integrated circuit device includes a control unit configured to control a switching element or an output transistor of a power supply device, a monitor terminal for monitoring an output voltage of the power supply device, a test unit configured to output a test signal to the monitor terminal before activation of the power supply device, and a determination unit configured to determine whether or not the monitor terminal is open, on the basis of a voltage of the monitor terminal when the test unit outputs the test signal to the monitor terminal.

A highly linear time amplifier with power supply rejection. In a reset stage, the threshold value of an over-threshold detector is used for resetting an output node of an amplifier, to eliminate the impact of power supply voltage changes on the threshold value of the threshold detector. A node capacitor unit is charged under the control of an input clock signal. After completion of charging, the node capacitor unit is discharged under the control of a synchronous clock signal. The time amplification gain only depends on the proportion of the charge and discharge current, and the charging and discharging time are completely linear in principle, which eliminates the nonlinearity of the traditional time amplifier, and reduces the negative impact of threshold change on system performance.

A highly linear time amplifier with power supply rejection. In a reset stage, the threshold value of an over-threshold detector is used for resetting an output node of an amplifier, to eliminate the impact of power supply voltage changes on the threshold value of the threshold detector. A node capacitor unit is charged under the control of an input clock signal. After completion of charging, the node capacitor unit is discharged under the control of a synchronous clock signal. The time amplification gain only depends on the proportion of the charge and discharge current, and the charging and discharging time are completely linear in principle, which eliminates the nonlinearity of the traditional time amplifier, and reduces the negative impact of threshold change on system performance.

A method can include, in response to a power supply voltage transition, setting a temperature window to a first temperature range by operation of a temperature circuit formed on a semiconductor device. In response to a temperature of the semiconductor device being determined to be outside of the first temperature range, changing the temperature range of the temperature window until the temperature of the semiconductor device is determined to be within the temperature window.

A power management circuit includes both a power on reset (POR) circuit and a voltage monitoring circuit. Explicit testing of these circuits is accomplished by controlling voltages applied to the circuits and monitoring an output signal responsive to a logical combination of outputs from the POR circuit and voltage monitoring circuit. The applied voltages are controlled with respect to timing of application, fixing of voltages and varying of voltages in a manner where a certain one of the circuits for explicit test is isolated with change in logic state of the output signal being indicative of operation of that isolated circuit.

A power management circuit includes both a power on reset (POR) circuit and a voltage monitoring circuit. Explicit testing of these circuits is accomplished by controlling voltages applied to the circuits and monitoring an output signal responsive to a logical combination of outputs from the POR circuit and voltage monitoring circuit. The applied voltages are controlled with respect to timing of application, fixing of voltages and varying of voltages in a manner where a certain one of the circuits for explicit test is isolated with change in logic state of the output signal being indicative of operation of that isolated circuit.

There has been a problem in semiconductor apparatuses of related art in which a circuit operation cannot be returned after a reverse current occurred. In one embodiment, a semiconductor apparatus includes a timer block configured to count up a count value to a predetermined value in response to a control signal being enabled, the control signal instructing a power MOS transistor to be turned on, and a protection transistor including a drain connected to a gate of the power MOS transistor, a source and a back gate connected to a source of the power MOS transistor, and an epitaxial layer in which the power MOS transistor is formed, the epitaxial layer being supplied with a power supply voltage. The protection transistor short-circuits the source and gate of the power MOS transistor in response to an output voltage of the power MOS transistor meeting a predetermined condition and the count value reaching the predetermined value. The timer block resets the count value when the output voltage of the power MOS transistor no longer meets the predetermined condition.

A semiconductor device includes a hysteresis block configured to generate an output voltage at corresponding disabling enabling voltage levels and a core-voltage-gated (CVG) device configured to receive a core voltage, an input terminal of the hysteresis block is coupled to a control node. The CVG device is configured to alter a control voltage at the control node so as to cause the output voltage of the hysteresis block to be generated at the disabling voltage level in response to the core voltage being at or below a first trigger level. Additionally, the CVG device is configured to alter the control voltage at the control node so as to cause the output voltage of the hysteresis block to be generated at the enabling voltage level in response to the core voltage being at or above a second trigger level, the second trigger level being above the first trigger level.

A current path to a gate is cut off by a normally-off first switch element until start-up of a gate drive voltage generator is sensed. Furthermore, a semiconductor switching element is maintained in an off state as a normally-on second switch element short-circuits the gate to a source. As start-up of the gate drive voltage generator is sensed, the second switch element is turned off and the first switch element is turned on. As the gate is thus driven by an output from a signal amplifier in accordance with a control signal, the semiconductor switching element is turned on and off in accordance with the control signal.