OVERCURRENT PROTECTION CIRCUIT
First Claim
1. An overcurrent protection circuit comprising:
- a load drive section driving a load;
a wire coupled with the load and the load drive section;
a current detection section detecting a load current value of an electric current that flows to the load, the current detection section including an AD converter and a current value calculation circuit, the AD converter receiving a detection signal corresponding to the load current value and analog-to-digital converting the detection signal, the current value calculation circuit calculating the load current value from the detection signal converted by the AD converter;
an addition and subtraction section determining an addition and subtraction value based on the load current value detected by the current detection section, storing an integration result of addition and subtraction using the addition and subtraction value, and transmitting the integration result, the addition and subtraction section including an addition value determination circuit, the addition value determination circuit determining an addition value in the addition and subtraction value based on the load current value calculated by the current value calculation circuit and a function expression or information indicating a relationship between the load current value and the addition value;
a comparison circuit comparing the integration result transmitted from the addition and subtraction section with a threshold value and transmitting a signal indicating an overcurrent detection result; and
a control circuit controlling the load drive section based on the signal indicating the overcurrent detection result transmitted from the comparison circuit to limit the electric current that flows to the load and the wire and to protect a protection object from an overcurrent.
1 Assignment
0 Petitions
Accused Products
Abstract
An overcurrent protection circuit includes a load drive section driving a load, a wire coupled with the load and the load drive section, a current detection section detecting a load current value of an electric current that flows to the load, an addition and subtraction section determining an addition and subtraction value based on the load current value and transmitting an integration result of addition and subtraction, a comparison circuit comparing the integration result with a threshold value, and a control circuit controlling the load drive section based on the comparison result. The addition and subtraction section includes an addition value determination circuit that determines an addition value in the addition and subtraction value based on the load current value and a function expression or information indicating a relationship between the load current value and the addition value.
20 Citations
26 Claims
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1. An overcurrent protection circuit comprising:
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a load drive section driving a load; a wire coupled with the load and the load drive section; a current detection section detecting a load current value of an electric current that flows to the load, the current detection section including an AD converter and a current value calculation circuit, the AD converter receiving a detection signal corresponding to the load current value and analog-to-digital converting the detection signal, the current value calculation circuit calculating the load current value from the detection signal converted by the AD converter; an addition and subtraction section determining an addition and subtraction value based on the load current value detected by the current detection section, storing an integration result of addition and subtraction using the addition and subtraction value, and transmitting the integration result, the addition and subtraction section including an addition value determination circuit, the addition value determination circuit determining an addition value in the addition and subtraction value based on the load current value calculated by the current value calculation circuit and a function expression or information indicating a relationship between the load current value and the addition value; a comparison circuit comparing the integration result transmitted from the addition and subtraction section with a threshold value and transmitting a signal indicating an overcurrent detection result; and a control circuit controlling the load drive section based on the signal indicating the overcurrent detection result transmitted from the comparison circuit to limit the electric current that flows to the load and the wire and to protect a protection object from an overcurrent. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An overcurrent protection circuit comprising:
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a load drive section driving a plurality of loads; a current detection section detecting an electric current flowing to each of the loads and transmitting a current detection value corresponding to the electric current; and a control section including an overcurrent level determination section and an addition and subtraction section, the control section turns on and off the load drive section based on an input condition, the overcurrent level determination section determining an overcurrent level of the current detection value, the addition and subtraction section adding and subtracting predetermined values corresponding to the current detection value based on a determination result of the overcurrent level determination section, wherein the addition and subtraction section adds and subtracts the predetermined values corresponding to the current detection value at the present time with respect to a calculation result using predetermined values corresponding to the current detection value at the last time, and the control section controls the load drive section to limit the electric current flowing to a corresponding one of the loads when a calculation result of the addition and subtraction section is greater than a determination threshold value, wherein the current detection section includes a comparison circuit, a channel switching circuit, and a threshold switching circuit, the comparison circuit includes a comparator transmitting the current detection value, wherein output terminals respectively coupled with the loads are regarded as channels, the channel switching circuit selects one of the channels, and transmits a voltage corresponding to the electric current flowing to a selected channel to the comparator, and wherein the threshold switching circuit sets a plurality of threshold values for each of the channels, the threshold switching circuit transmits the threshold values of the selected channel in turn to the comparator. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification