Power delivery circuit with current detection
First Claim
1. A current detection circuit in combination with a current controlling device in a power delivery circuit for supplying load current to a load, the current controlling device being multicellular, with a major current-carrying cellular portion and a minor current-carrying cellular portion, a first main current terminal for connection to a source of power, a gate terminal for receiving a control signal, a second main current terminal connecting the major current-carrying cellular portion, a first auxiliary terminal connected at one end to the minor current-carrying cellular portion so as to provide a current generally proportional to the main device current, and a second auxiliary terminal connected at one end to the major current-carrying cellular portion, and wherein the current detection circuit comprises:
- first and second branches each for connection at one end to a respective one of said first and said second auxiliary terminals and having means for connection in common at the other end to a reference potential in the power delivery circuit;
said first branch including a first series-connected semiconductor device;
said first branch including a second series-connected semiconductor device;
said first semiconductor device operating in a transimpedance mode and being controlled by a bias signal;
said second semiconductor device being cross-connected with said first semiconductor device to provide the respective said bias signal thereto;
a first node providing a signal approximately proportional to the main device current; and
wherein said second semiconductor is connected in said second branch in a manner providing a bias signal for controlling said first semiconductor so as to result in said signal at said node being proportional to the main device current within a relatively small tolerance range across a relatively broad operating range.
4 Assignments
0 Petitions
Reexamination
Accused Products
Abstract
A power delivery circuit for supplying load current to a load includes a current switch connected on the high potential side of a load. In order to detect a current condition, such as an over-current condition in the load, a current sensing and detection circuit preferably cooperates with the current switch wherein such switch comprises a multicellular device with a plurality of terminals. Such terminals include a first main current terminal connected to a source of high potential, a second main current terminal connecting a majority of device cells to the load, a first auxiliary terminal connected at one end to a minority of device cells so as to provide a current generally proportional to the main device current, and a second auxiliary terminal connected at one end to a majority of device cells. The current detection circuit preferably comprises one branch connected between the first auxiliary terminal and ground and including, in serial circuit, a current-to-voltage converting resistor providing a voltage at one end approximately proportional to the main device current and a bias signal-controlled transimpedance device, and another branch connected between the second auxiliary terminal and ground and providing a bias signal for the transimpedance device in the first branch.
49 Citations
48 Claims
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1. A current detection circuit in combination with a current controlling device in a power delivery circuit for supplying load current to a load, the current controlling device being multicellular, with a major current-carrying cellular portion and a minor current-carrying cellular portion, a first main current terminal for connection to a source of power, a gate terminal for receiving a control signal, a second main current terminal connecting the major current-carrying cellular portion, a first auxiliary terminal connected at one end to the minor current-carrying cellular portion so as to provide a current generally proportional to the main device current, and a second auxiliary terminal connected at one end to the major current-carrying cellular portion, and wherein the current detection circuit comprises:
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first and second branches each for connection at one end to a respective one of said first and said second auxiliary terminals and having means for connection in common at the other end to a reference potential in the power delivery circuit; said first branch including a first series-connected semiconductor device; said first branch including a second series-connected semiconductor device; said first semiconductor device operating in a transimpedance mode and being controlled by a bias signal; said second semiconductor device being cross-connected with said first semiconductor device to provide the respective said bias signal thereto; a first node providing a signal approximately proportional to the main device current; and wherein said second semiconductor is connected in said second branch in a manner providing a bias signal for controlling said first semiconductor so as to result in said signal at said node being proportional to the main device current within a relatively small tolerance range across a relatively broad operating range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 48)
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13. A current detection circuit for use in combination with a current controlling device in a power delivery circuit for supplying load current to a load, the current controlling device being multicellular, with a major current-carrying cellular portion and a minor current-carrying cellular portion, a first main current terminal for connection to a source of power, a gate terminal for receiving a control signal, a second main current terminal connecting the major current-carrying cellular portion, a first auxiliary terminal connected at one end to the minor current-carrying cellular portion so as to provide a current generally proportional to the main device current, and a second auxiliary terminal connected at one end to the major current-carrying cellular portion, the current detection circuit comprising:
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first and second branches each for connection at one end to a respective one of said first and said second auxiliary terminals and having means for connection in common at the other end to a reference potential in the power delivery circuit; said first branch including a first bipolar transistor with its emitter and collector connected in series therein; said second branch including a second bipolar transistor with its emitter and collector connected in series therein; said first bipolar transistor operating in a transimpedance mode and being controlled by a bias signal; said second bipolar transistor having its base shorted to its collector and cross-connected to the base of said first bipolar transistor to provide the respective said bias signal thereto; and said first branch further including impedance means connected in series circuit with said first bipolar transistor for providing a voltage approximately proportional to the main device current at a node at one end of said impedance means. - View Dependent Claims (14, 15)
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16. A power delivery circuit of the H-bridge type including:
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a load leg having two end nodes and means to connect to a load; a power means for connection to a source of electrical power having a predetermined nominal voltage for supplying current to the load; a ground means for providing a path for returning load current to the source of electrical power; a first current path for supplying load current through the load in a first direction comprising a first high potential leg connected between the power means and a first end node of the load leg, and a first low potential leg connected between a second end node of the load leg and the ground means; and a second current path for supplying load current through the load in a second direction comprising a second high potential leg connected between the power means and the second end node of the load leg, and a second low potential leg connected between the first end node of the load leg and the ground means; the high and low potential legs each including a respective current switch, each said high potential leg current switch being multicellular with a plurality of terminals, including a first main current terminal connected to the power means, a second main current terminal connecting a majority of device cells to a respective end node of the load leg, a control terminal for controlling the switching state of the switch in response to a control signal, a first auxiliary terminal connected to one end of a minority of switch cells so as to provide a current generally proportional to the main switch current, and a second auxiliary terminal connected at one end to the majority of switch cells; the power delivery circuit further comprising first and second current detection circuits responsive to electrical conditions in the first and second high potential legs, respectively, for detecting the current level in either of such legs; each current detection circuit comprising a first branch connected between the first auxiliary terminal and the ground means and including in serial circuit, a resistor providing a voltage at one end approximately proportional to the main switch current and a bias signal-controlled first bipolar transistor, and a second branch connected between the second auxiliary terminal and the ground means and including in serial circuit, a second bipolar transistor, the base of the second transistor being shorted to its collector and being connected to the base of the first transistor for providing a bias signal for the first transistor in the first branch whereby said voltage at said resistor one end is proportional to the actual main switch current within ±
3% for variations in the source voltage in a range of at least ±
25% of said nominal source voltage and variations between 100 and 500 in the gains (β
) of said first and second transistors. - View Dependent Claims (17, 18, 19)
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20. A power delivery circuit for supplying load current to a load comprising:
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(a) a power node for connection to a source of electrical power; (b) a load node for connection to a load; (c) a high potential current path for supplying electrical current from the power node to the load node and including a current switch whose switching state is controlled by a control signal on an associated control terminal;
said current switching having first and second main terminals, a first auxiliary terminal which produces a current which is a predetermined fraction of the total current in the high potential current path, and a second auxiliary terminal connected to one of the main terminals of the current switch;(d) a current detection circuit responsive to an electrical condition of the high potential current path and being for detecting the current level in the high potential current path;
the current detection circuit comprising;(1) a first branch connected to one of said first and second auxiliary terminals and comprising a first semiconductor device; (2) a second branch connected to the other of said first and second auxiliary terminals and comprising a second semiconductor device; (3) said second semiconductor device being interconnected to said first semiconductor device in a current mirror configuration so as to maintain said first and second auxiliary terminals at substantially the same voltage; and (4) a first node providing a signal approximately proportional to load current. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A power delivery circuit for supplying load current to a load, comprising:
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a power node for connection to a source of electrical power; a load node for connection to a load; a high potential current path for supplying electrical current from the power node to the load node and including a current switch whose switching state is controlled by a control signal on an associated control terminal;
said current switch having first and second main terminals, a first auxiliary terminal which produces a current which is a predetermined fraction of the total current in the high potential current path, and a second auxiliary terminal connected to one of the main terminals of the current switch;a current detection circuit responsive to an electrical condition of the high potential current path and being for detecting the current level in the high potential current path;
the current detection circuit comprising one branch connected between one of the first and second auxiliary terminals and a ground and including a bias signal-controlled transimpedance device and another branch connected between the other of the first and second auxiliary terminals and the ground and providing a bias signal for the transimpedance device in the first branch, and a first node providing a signal approximately proportional to the main device current. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39)
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40. A power delivery circuit of the H-bridge type including:
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a load leg having two end nodes and means to connect to a load; a power means for connection to a source of electrical power for supplying current to the load;
said power means having a first auxiliary terminal and a second auxiliary terminal;
said first auxiliary terminal producing current which is a predetermined fraction of the total current through said power means;a ground means for providing a path for returning load current to the source of electrical power; a first current path for supplying load current through the load in a first direction comprising a first high potential leg connected between the power means and a first end node of the load leg, and a first low potential leg connected between a second end node of the load leg and the ground means; and a second current path for supplying load current through the load in a second direction comprising a second high potential leg connected between the power means and the second end node of the load leg, and a second low potential leg connected between the first end node of the load leg and the ground means; the high and low potential legs each including a respective current switch whose switching state is controlled by a control signal on an associated control terminal; the power delivery circuit further comprising first and second current detection circuits responsive to electrical conditions in the first and second high potential legs, respectively for detecting the current level in either of such legs; each current detection circuit comprising one branch connected between one of the first and second auxiliary terminals and the ground means and including a bias signal-controlled transimpedance device and another branch connected between the other of the first and second auxiliary terminals and the ground means and providing a bias signal for the transimpedance device in the first branch and a first node providing a signal approximately proportional to the main device current. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47)
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Specification