US5436581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for monitoring the drain current of a metal oxide semiconductor field effect transistor
Assignee: Texas Instruments Inc
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Filing: 1994-12-07
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Granted: 1995-07-25
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Expires: 2014-12-07
Abstract
Abstract In the case of a circuit arrangement for monitoring the drain current of a metal oxide semiconductor field effect transistor T o whose effective transistor area is subdivided in order to provide an MOS measuring transistor T o ' and an MOS power transistor T o " the drain-source paths of the two MOS transistor sections T o' , T o " are placed in different current loops SZ 1 , SZ b of a current mirror SP1, which is acted upon by a predeterminable reference current I ref . The current mirror SP1 has an output terminal E, which supplies a monitoring signal dependent on the difference between the drain-source voltages of the two MOS field effect transistors T o' , T o ".
Inventors
- 👤 Johann Oberhauser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:15
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/26; G01R31/2607; G01R31/2621; G01R31/28; G01R31/317; G01R31/31712; G01R31/31715
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
153 words
A circuit arrangement for monitoring the drain current (I DS ) of a metal oxide semiconductor field effect (MOS) transistor (T O ) whose effective transistor area formed on a substrate is subdivided in order to provide an MOS measuring transistor (T O ') supplying a measuring current (I M ) and an MOS power transistor (T O ") supplying a power output, characterized in that the drain-source paths (D - S) of the MOS measuring transistor (T O ') and of the MOS power transistor (T O ") are placed in different current loops (SZ a , SZ b ) of a current mirror (SP1), which is acted upon by a predeterminable reference current (I ref ) and has an output terminal (E), which supplies a monitoring signal dependent on the difference between the drain-source voltages (U DS ) of the two MOS field effect transistors (T O ', T O ").
Claim 2
Dependent Claim
153 words
A circuit arrangement for monitoring the drain current (I DS ) of a metal oxide semiconductor field effect (MOS) transistor (T O ) whose effective transistor area formed on a substrate is subdivided in order to provide an MOS measuring transistor (T O ') supplying a measuring current (I M ) and an MOS power transistor (T O ") supplying a power output, characterized in that the drain-source paths (D - S) of the MOS measuring transistor (T O ') and of the MOS power transistor (T O ") are placed in different current loops (SZ a , SZ b ) of a current mirror (SP1), which is acted upon by a predeterminable reference current (I ref ) and has an output terminal (E), which supplies a monitoring signal dependent on the difference between the drain-source voltages (U DS ) of the two MOS field effect transistors (T O ', T O ").
Claim 3
Dependent Claim
38 words
The circuit arrangement as claimed in claim 1, characterized in that the predeterminable reference current (I ref ) is fed to the current mirror (SP1) comprising the two MOS field effect transistors (T O ', T O ").
Claim 4
Dependent Claim
67 words
The circuit arrangement as claimed in claim 1, characterized in that the MOS measuring transistor (T O ') and the MOS power transistor (T O ") in the respective current mirror loop (SZ a , SZ b ) are each connected in series with a transistor (T 4 , T 5 ) which is connected via an emitter resistor (R 2 , R 3 ) with ground.
Claim 5
Dependent Claim
60 words
The circuit arrangement as claimed in claim 1, characterized in that in the respective current mirror loop (SZ a , SZ b ) the MOS measuring transistor (T O ') and the MOS power transistor (T O ") are each connected in series with two mutually complementary transistors (T 1 , T 4 ; T 2 , T 5 ).
Claim 6
Dependent Claim
60 words
The circuit arrangement as claimed in claim 4, Characterized in that the monitoring output terminal (E) of the current mirror (SP1) is constituted by the two collectors, which are connected with one another, of the two complementary transistors (T 2 , T 5 ) in the current mirror loop (SZ b ) containing the MOS power transistor (T O ").
Claim 7
Dependent Claim
39 words
The circuit arrangement as claimed in claim 5, characterized in that an output stage (14) comprising two mutually complementary transistors (T 6 , T 7 ) is connected to the monitoring output terminal (E) of the current mirror (SP1).
Claim 8
Dependent Claim
39 words
The circuit arrangement as claimed in claim 1, characterized in that the current mirror (SP1) having the monitoring output terminal (E) is connected to an output stage (14) which is connected with a following TTL level adapting stage (16).
Claim 9
Dependent Claim
72 words
The circuit arrangement as claimed in claim 2, characterized in that a further current mirror (SP2) comprises an input current loop (SZ e ) connected with a constant voltage (V stab ), in which a reference resistor (R ref ) is connected in series with a transistor diode (T 3 ), which is connected via an emitter resistor (R1) with ground (M); wherein the further current mirror controls the predetermined reference current.
Claim 10
Dependent Claim
28 words
The circuit arrangement as claimed in claim 1, characterized in that the metal oxide semiconductor field effect transistor (T O ) is a double diffused MOS (D-MOS) transistor.
Claim 11
Dependent Claim
56 words
The circuit arrangement as claimed in claim 9, characterized in that the metal oxide semiconductor field effect transistor (T O ) is a D-MOS transistor of the HSD (high side driver) type, in the case of which in the turned on state of the transistor the gate electrode has a higher potential than the drain electrode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-24 | 1999-01-23 | 1999-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-24 | 2003-01-23 | 2003-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-24 | 2007-01-23 | 2007-07-25 | $7700.00 | Window Closed / Lapsed |