A supply circuit has a first and a second terminal for connecting an accumulator, a third and a fourth terminal for connecting at least one battery, and an output terminal. A voltage regulator is connected to the first terminal on the input side and to a fifth terminal on the output side. An undervoltage detection circuit is adapted to activate the voltage regulator when a voltage at the first terminal is greater than a threshold voltage. A reverse polarity protection device is coupled between the third terminal and the output terminal. A blocking diode is coupled between the fifth terminal and the output terminal.

A semiconductor device includes first to N-th voltage output circuits each outputting an output voltage and outputs a feedback voltage having a voltage value corresponding to the output voltage, and a differential circuit including first to N-th primary side transistors to which N feedback voltages are input and that individually flow first to N-th currents through a first node, a secondary side transistor that flows a reference current corresponding to a reference voltage through the first node, and a current mirror circuit as an active load. The current mirror circuit includes first to N-th primary side load transistors individually coupled in cascade to the first to N-th primary side transistors, a secondary side load transistor coupled in cascade to the secondary side transistor and generates a voltage at a connection point between the secondary side transistor and the secondary side load transistor as a control voltage.

A semiconductor device includes first to N-th voltage output circuits each outputting an output voltage and outputs a feedback voltage having a voltage value corresponding to the output voltage, and a differential circuit including first to N-th primary side transistors to which N feedback voltages are input and that individually flow first to N-th currents through a first node, a secondary side transistor that flows a reference current corresponding to a reference voltage through the first node, and a current mirror circuit as an active load. The current mirror circuit includes first to N-th primary side load transistors individually coupled in cascade to the first to N-th primary side transistors, a secondary side load transistor coupled in cascade to the secondary side transistor and generates a voltage at a connection point between the secondary side transistor and the secondary side load transistor as a control voltage.

Disclosed herein is a single integrated circuit chip with a main logic that operates a vehicle component such as a valve driver. Isolated from the main logic within the chip is a safety area that operates to verify proper operation of the main logic. The safety area is internally powered by an internal regulated voltage generated by an internal voltage regulator that generates the internal regulated voltage from an external voltage while protecting against shorts of the external line delivering the external voltage. The safety area includes protection circuits that level shift external analog signals downward in voltage for monitoring within the safety area, the protection circuits serving to protect against shorts of the external line delivering the external analog signals.

Disclosed herein is a single integrated circuit chip with a main logic that operates a vehicle component such as a valve driver. Isolated from the main logic within the chip is a safety area that operates to verify proper operation of the main logic. The safety area is internally powered by an internal regulated voltage generated by an internal voltage regulator that generates the internal regulated voltage from an external voltage while protecting against shorts of the external line delivering the external voltage. The safety area includes protection circuits that level shift external analog signals downward in voltage for monitoring within the safety area, the protection circuits serving to protect against shorts of the external line delivering the external analog signals.

A first terminal receives a first DC voltage. A switch selectively couples the first terminal to a second terminal providing an output. A control circuit selectively actuates the switch in response to a comparison of the first DC voltage to a second DC voltage. A low-dropout (LDO) linear voltage regulator, connected between the first and third terminals, operates to provide the second DC voltage from the first DC voltage.

A first terminal receives a first DC voltage. A switch selectively couples the first terminal to a second terminal providing an output. A control circuit selectively actuates the switch in response to a comparison of the first DC voltage to a second DC voltage. A low-dropout (LDO) linear voltage regulator, connected between the first and third terminals, operates to provide the second DC voltage from the first DC voltage.

In an embodiment, a method includes: receiving a main supply voltage; generating a first regulated output voltage with a DC-DC converter; providing the main supply voltage to a driver of a control terminal of an output transistor of an LDO; receiving, at an input terminal of the LDO, the first regulated output voltage; generating, at an output terminal of the LDO, a second regulated output voltage from the first regulated output voltage; and when the main supply voltage falls below a predetermined threshold, discharging a capacitor coupled to the input terminal of the LDO by activating a switch coupled to the input terminal of the LDO.

In an embodiment, a method includes: receiving a main supply voltage; generating a first regulated output voltage with a DC-DC converter; providing the main supply voltage to a driver of a control terminal of an output transistor of an LDO; receiving, at an input terminal of the LDO, the first regulated output voltage; generating, at an output terminal of the LDO, a second regulated output voltage from the first regulated output voltage; and when the main supply voltage falls below a predetermined threshold, discharging a capacitor coupled to the input terminal of the LDO by activating a switch coupled to the input terminal of the LDO.

An apparatus comprises a first circuit, a second circuit, a first transistor, a second transistor, a third transistor, a first programmable resistance, and a second programmable resistance. The first circuit may be configured to generate a reference signal and a bias signal in response to a supply voltage and a first input signal. The first circuit generally provides supply noise rejection to variations in the supply voltage. The second circuit may be connected to the first circuit and a ring oscillator. The first transistor may be connected to the first circuit and configured to set a first reference current of the first circuit based on the first input signal and the first programmable resistance. The second transistor may be connected in parallel with the first transistor. The second transistor is generally diode-connected. The third transistor may be connected to the first circuit and configured to set a second reference current of the first circuit based on the first input signal and the second programmable resistance. The first circuit generally forms a current mirror with the second circuit. The second circuit may be configured to provide a programmable current ratio for the current mirror based on a value of a second input signal.