Voltage detection device having trimming resistors and capable of determining resistance value of trimming resistors without additional terminals for monitoring internal circuit

A voltage detection device comprising:

• a first detection terminal to which a first input voltage is applied;
• a second detection terminal to which a second input voltage is applied;
• a reference voltage source configured to produce a predetermined reference voltage;
• a comparison circuit having first and second input terminals, and configured to output a signal indicating a higher one of two voltages respectively applied to the first and second input terminals, the first input terminal being connected to the first detection terminal;
• voltage divider resistors connected between the reference voltage source and the second detection terminal, and having an intermediate terminal at which an intermediate voltage between the reference voltage and the second input voltage is produced, the voltage divider resistors including trimming resistors having a variable resistance value;
• and
• a switch circuit configured to connect one of the second detection terminal and the intermediate terminal to the second input terminal.

A voltage detection device comprising:

• a first detection terminal to which a first input voltage is applied;
• a second detection terminal to which a second input voltage is applied;
• a comparison circuit having first and second input terminals, and configured to output a signal indicating a higher one of two voltages respectively applied to the first and second input terminals;
• a reference voltage source connected between the first detection terminal and the first input terminal, and configured to produce a predetermined reference voltage and adds the reference voltage to the first input voltage;
• voltage divider resistors connected between the first and second detection terminals, and having an intermediate terminal at which an intermediate voltage between the first and second input voltages is produced, the voltage divider resistors including trimming resistors having a variable resistance value;
• and
• a switch circuit configured to connect one of the second detection terminal and the intermediate terminal to the second input terminal.

A voltage detection device comprising:

• a detection terminal to which an input voltage is applied;
• a reference voltage source configured to produce a predetermined reference voltage;
• a comparison circuit having a control terminal, and configured to output a signal indicating a higher one of a voltage applied to the control terminal and a predetermined threshold voltage;
• voltage divider resistors connected between the reference voltage source and the detection terminal, and having an intermediate terminal at which an intermediate voltage between the reference voltage and the input voltage is produced, the voltage divider resistors including trimming resistors having a variable resistance value;
• and
• a switch circuit configured to connect one of the detection terminal and the intermediate terminal to the control terminal.

A test method for a voltage detection device,

• wherein the voltage detection device comprises:
• a first detection terminal to which a first input voltage is applied;
• a second detection terminal to which a second input voltage is applied;
• a reference voltage source configured to produce a predetermined reference voltage;
• a comparison circuit having first and second input terminals, and configured to output a signal indicating a higher one of two voltages respectively applied to the first and second input terminals;
• first voltage divider resistors connected between the reference voltage source and the first detection terminal, and having a first intermediate terminal at which a first intermediate voltage between the reference voltage and the first input voltage is produced;
• a first switch circuit configured to connect one of the first detection terminal and the first intermediate terminal to the first input terminal;
• second voltage divider resistors connected between the reference voltage source and the second detection terminal, and having a second intermediate terminal at which a second intermediate voltage between the reference voltage and the second input voltage is produced, the second voltage divider resistors including trimming resistors having a variable resistance value;
• and
• a second switch circuit configured to connect one of the second detection terminal and the second intermediate terminal to the second input terminal,
• wherein the test method includes:
• applying a predetermined first test voltage to the first detection terminal;
• applying a variable second test voltage to the second detection terminal;
• controlling connections of the first and second switch circuits according to one of a plurality of modes;
• monitoring, in each of the plurality of modes, a signal outputted from the comparison circuit while sweeping the second test voltage;
• and
• determining the resistance value of the trimming resistors based on the signal outputted from the comparison circuit, such that a transition of the signal outputted from the comparison circuit occurs when the first and second input voltages have a predetermined target voltage difference, and setting the resistance value to the trimming resistors.