High-current, bidirectional protection circuits and methods
AssigneeMaxim Integrated Products, Inc.
InventorGabriel Eugen Tanase
Life of this patent
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Abstract
Systems and methods herein use a sensing circuit to detect an overvoltage at a voltage node as a drain current. A current-mode comparator converts the detected current into a control signal, which is provided to a control circuit. The control circuit uses the control signal cut of a bias current to turn off switches in a protection circuit to create a high-impedance electrical path between the voltage node and the to-be-protected voltage node.
Claims20
An overcurrent protection method comprising:
- using a sensing circuit that, in response to an overcurrent condition being present at a current node, detects a current;
- using a current-mode comparator to convert the current to a control signal;
- and
- using a control circuit that, in response receiving the control signal, turns off a set of switching devices that are coupled to a to-be-protected current node to create a high-impedance electrical path between the current node and the to-be-protected current node.
A dual-polarity high-current protection circuit comprising:
- a protection circuit coupled to a to-be-protected current node and an output current node;
- a current sensing circuit that, in response to sensing an overcurrent condition present at the output current node, generates an output signal indicative of the overcurrent condition;
- and
- a control circuit coupled to the current sensing circuit, the control circuit, in response to receiving the output signal, causes the protection circuit to assume a high impedance to isolate the to-be-protected current node from the overcurrent condition.
A switch network for bidirectional high-current protection of a current node, the switch network comprising:
- two sets of switches that each is coupled to a to-be-protected current node and an output current node, which in normal operation assumes a current within a current range;
- a set of comparators that each is coupled to a switch in a third set of switches, respectively, and generates a low-level signal to control bias currents to cause the two sets of switches to turn on, such that a current flowing between the to-be-protected current node and the output current node is determined by on-resistances of the two sets of switches and a load voltage present at the output current node;
- and
- in response to the current at the output current node falling outside the current range, a drain current exceeding a current value causing a corresponding comparator in the set of comparators generating a high-level signal that causes the bias currents and, thus, the two sets of switches to turn off, thereby, creating a high-impedance path between the to-be-protected current node and the output current node, the current at the to-be-protected current node being controlled by an output stage state of an operational amplifier to be within the current range, the current at the output current node assuming values between a lower current threshold and a higher current threshold.
Dependencies are inferred from the claim text.