A microcontroller is coupled to a detection circuit which generates a detection signal. The microcontroller includes a processing circuit and an input-output circuit. The processing circuit generates an output signal according to the detection signal. In response to the output signal being at a specific level, the processing circuit enables a reset signal. The input-output circuit includes a latch circuit and a counter circuit. The latch circuit latches the output signal to generate a latched signal. The counter circuit starts adjusting the count value in response to the reset signal being enabled. The counter circuit changes the level of the latched signal in response to the count value being equal to a predetermined value.

An improved circuit or method generates first and second initial pulses that do not overlap. First and second drive pulses are generated based on the first and second initial pulses, respectively. A first transistor is turned on with the first drive pulses. A second transistor is turned on with the second drive pulses. A current flows in response to an on-time state of the first transistor overlapping with an on-time state of the second transistor. A delay of the second drive pulses is decreased based on a time of the current flow overlapping with one of the first initial pulses; and the delay of the second drive pulses is increased based on the time of the current flow overlapping with one of the second initial pulses.

An improved circuit or method generates first and second initial pulses that do not overlap. First and second drive pulses are generated based on the first and second initial pulses, respectively. A first transistor is turned on with the first drive pulses. A second transistor is turned on with the second drive pulses. A current flows in response to an on-time state of the first transistor overlapping with an on-time state of the second transistor. A delay of the second drive pulses is decreased based on a time of the current flow overlapping with one of the first initial pulses; and the delay of the second drive pulses is increased based on the time of the current flow overlapping with one of the second initial pulses.

An analog counter circuit for use with a digital pixel includes an input; an output; a first inverter connected to the input that produces on a first inverter output a time delayed inverted signal (RP*) from an input signal received at the input; a second inverter connected to the first inverter output that produces a time delayed signal (RP) at a second inverter output from the input signal and that is delayed relative to RP* and a control switch connected between a source voltage and a floating node. The control switch is controlled by the signal RP* on the first inverter output. The analog counter also includes a feedback capacitor connected between the second inverter output and the floating node; an accumulating capacitor that accumulates at least some of a charge that passes through the control switch; and an injection switch connected between the control switch and the accumulating capacitor.

An analog counter circuit for use with a digital pixel includes an input; an output; a first inverter connected to the input that produces on a first inverter output a time delayed inverted signal (RP*) from an input signal received at the input; a second inverter connected to the first inverter output that produces a time delayed signal (RP) at a second inverter output from the input signal and that is delayed relative to RP* and a control switch connected between a source voltage and a floating node. The control switch is controlled by the signal RP* on the first inverter output. The analog counter also includes a feedback capacitor connected between the second inverter output and the floating node; an accumulating capacitor that accumulates at least some of a charge that passes through the control switch; and an injection switch connected between the control switch and the accumulating capacitor.

A method includes protecting a boot sequence of a processing device by incrementing a counting value generated by a monotonic counter, then a first time period after the beginning of the boot sequence, comparing, by the protection circuit, the counting value with a first reference value, and, if the counting value is smaller than the first reference value, changing, by the protection circuit, the counting value to the first reference value.

A method of resetting a digital counter for a personal care appliance by sending an electrical output signal from an optical sensor to a control circuit. The electrical output signal is compared to a predetermined value with the control circuit or a change in the electrical output signal from the optical sensor is detected over time. A signal is sent to a consumer user interface by the control circuit based on the electrical output signal and the predetermined value or based on the change in the electrical output signal from the optical sensor. The digital counter is reset based on an input signal from the consumer user interface.

A method of resetting a digital counter for a personal care appliance by sending an electrical output signal from an optical sensor to a control circuit. The electrical output signal is compared to a predetermined value with the control circuit or a change in the electrical output signal from the optical sensor is detected over time. A signal is sent to a consumer user interface by the control circuit based on the electrical output signal and the predetermined value or based on the change in the electrical output signal from the optical sensor. The digital counter is reset based on an input signal from the consumer user interface.

An enable control circuit, which includes a counter circuit configured to count a current clock cycle and determine a clock cycle count value; a selection circuit configured to determine a clock cycle count target value according to a first setting signal; and a control circuit configured to control an ODT path to be enabled and start the counter circuit when the voltage level of an ODT pin signal is flipped over, control the ODT path to be switched from being enabled to disabled when the clock cycle count value reaches the clock cycle count target value and the voltage level of the ODT pin signal is not changed, and control the ODT path continue to be enabled when the clock cycle count value reaches the clock cycle count target value and the voltage level of the ODT pin signal flips again.

An enable control circuit, which includes a counter circuit configured to count a current clock cycle and determine a clock cycle count value; a selection circuit configured to determine a clock cycle count target value according to a first setting signal; and a control circuit configured to control an ODT path to be enabled and start the counter circuit when the voltage level of an ODT pin signal is flipped over, control the ODT path to be switched from being enabled to disabled when the clock cycle count value reaches the clock cycle count target value and the voltage level of the ODT pin signal is not changed, and control the ODT path continue to be enabled when the clock cycle count value reaches the clock cycle count target value and the voltage level of the ODT pin signal flips again.