US4553084A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current sensing circuit
Assignee: Semiconductor Components Industries LLC
•
Filing: 1984-04-02
•
Granted: 1985-11-12
•
Expires: 2004-04-02
Abstract
Abstract A current sensing circuit is disclosed wherein a small portion of a load current is sampled through a sensing resistor and a substantially larger portion of the load current is allowed to bypass the sensing resistor. A first high current vertical MOS transistor is coupled between the load and the ground terminal. A second vertical MOS transistor is coupled in series between the load and ground terminal. The transistors are constructed in a vertical MOS cellular construction whereby the first transistor comprises on the order of three-thousand cells and the second transistor comprises a single cell. A signal is taken across the sensing resistor and may be provided as feedback to a control means driving the first and second transistors for performing a current limiting or constant current function.
Inventors
- 👤 Robert S. Wrathall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:58
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/0092; G01R17/00; G01R17/02; G01R17/06; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/575; H; H02; H02M; H02M1/00; H02M1/0003; H02M1/0009; H10; H10D; H10D30/00; H10D30/60; H10D30/64; H10D30/66; H10D30/669
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
A current sensing circuit coupled between a load having a load current passing therethrough and a supply voltage terminal, comprising: a first current means coupled between said load and said supply voltage terminal for carrying a first portion of said load current; resistive means coupled to said supply voltage terminal for providing a voltage drop; second current means coupled between said load and said resistive means for carrying a second portion of said load current, said first portion being substantially larger than said second portion; control means coupled to said first current means and said second current means for biasing said first current means and said second current means; output means coupled to a first node between said second current means and said resistive means for providing an output.
Claim 2
Dependent Claim
129 words
A current sensing circuit coupled between a load having a load current passing therethrough and a supply voltage terminal, comprising: a first current means coupled between said load and said supply voltage terminal for carrying a first portion of said load current; resistive means coupled to said supply voltage terminal for providing a voltage drop; second current means coupled between said load and said resistive means for carrying a second portion of said load current, said first portion being substantially larger than said second portion; control means coupled to said first current means and said second current means for biasing said first current means and said second current means; output means coupled to a first node between said second current means and said resistive means for providing an output.
Claim 3
Dependent Claim
18 words
The current sensing circuit according to claim 1 wherein said first and second current means comprise MOS transistors.
Claim 4
Dependent Claim
48 words
The current sensing circuit according to claim 1 wherein said first and second current means comprise MOS transistors having a vertical construction, said first current means having a plurality of cells and said second current means having a number of cells substantially less than said first current means.
Claim 5
Dependent Claim
70 words
The current sensing circuit according to claim 1 wherein said first and second current means comprise MOS transistors havng a vertical construction, said circuit further comprising a third current means comprising an MOS transistor coupled between said load and a second node for carrying a third portion of said load current, said second node coupled to said output means and coupled to said supply voltage terminal by a current source.
Claim 6
Dependent Claim
106 words
A current sensing circuit having an input terminal for receiving a load current, a supply voltage terminal and an output terminal, comprising: a first transistor having current carrying electrodes coupled between said input terminal and said supply voltage terminal; a second transistor having a first current carrying electrode coupled to said input terminal; resistive means coupled between a second current carrying electrode of said second transistor and said supply voltage terminal for providing a voltage drop, wherein said second current carrying electrode is also coupled to said output terminal; and a drive circuit coupled to a control electrode of each of said first and second transistors.
Claim 7
Dependent Claim
106 words
A current sensing circuit having an input terminal for receiving a load current, a supply voltage terminal and an output terminal, comprising: a first transistor having current carrying electrodes coupled between said input terminal and said supply voltage terminal; a second transistor having a first current carrying electrode coupled to said input terminal; resistive means coupled between a second current carrying electrode of said second transistor and said supply voltage terminal for providing a voltage drop, wherein said second current carrying electrode is also coupled to said output terminal; and a drive circuit coupled to a control electrode of each of said first and second transistors.
Claim 8
Dependent Claim
16 words
The circuit according to claim 5 wherein said output terminal is coupled to said drive circuit.
Claim 9
Dependent Claim
41 words
The current sensing cricui according to claim 5 wherein said first and second transistors are MOS transistors, said first transistor having a plurality of cells and said second transistor having a number of cells substantially less than said first current means.
Claim 10
Dependent Claim
121 words
A circuit for providing a constant current to a load comprising: first current means coupled between said load and a supply voltage terminal for carrying a first portion of said current; resistive means coupled to said supply voltage terminal for providing a voltage drop; second current means coupled between said load and said resistive means for carrying a second portion of said current, said first portion being substantially larger than said second portion; control means coupled to said first and second current means for controlling the value of said first portion and said second portion; and drive means coupled from a node between said resistive means and said second current means to said control means and for driving said control means.
Claim 11
Dependent Claim
121 words
A circuit for providing a constant current to a load comprising: first current means coupled between said load and a supply voltage terminal for carrying a first portion of said current; resistive means coupled to said supply voltage terminal for providing a voltage drop; second current means coupled between said load and said resistive means for carrying a second portion of said current, said first portion being substantially larger than said second portion; control means coupled to said first and second current means for controlling the value of said first portion and said second portion; and drive means coupled from a node between said resistive means and said second current means to said control means and for driving said control means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-11 | 1989-05-13 | 1989-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-11 | 1993-05-13 | 1993-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-11 | 1997-05-13 | 1997-11-12 | $7700.00 | Window Closed / Lapsed |