Patent US5132866A successfully refreshed from Google Patents.
US5132866A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for protection against the formation of parasitic transistors in an integrated circuit for driving an inductive load
Assignee: STMicroelectronics SRL
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Filing: 1990-07-17
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Granted: 1992-07-21
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Expires: 2010-07-17
Abstract
Abstract A monolithic integrated circuit (M) includes a power device (Q3, Q4) for driving an inductive load (L) and a control device for the power device. The control device comprises a voltage limiting circuit which includes a first transistor (Q2) responsive to negative impulses of the supply voltage and a second transistor (Q5) which is controlled by the first transistor for controlling re-firing of the power device in case of a negative pulse of the power voltage during a quenching period of the power device. The monolithic integrated circuit includes a substrate (5) having a substrate surface forming a supply voltage terminal of the power device and having a substrate voltage. An annular pocket (40) is formed in the substrate to surround or at least partially contain at least the first transistor (Q2) of the voltage limiting circuit. According to differing modes of the invention, the annular pocket (40) is biased at a voltage depending on that of the supply voltage terminal of the power device; is left at a floating potential. In one embodiment a pocket (3) is surrounded by an area of a different conductivity type (70) which has a grounded contact distributed along an emerging portion thereof.
Inventors
- 👤 Salvatore Raciti
- 👤 Sergio Palara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:48
CPC Classifications
H; H10; H10D; H10D89/00; H10D89/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
165 words
A monolithic integrated circuit including a power device for driving an inductive load and a control device for said power device, said control device comprising a voltage limiting circuit essentially constituted by a first transistor responsive to negative pulses of a supply voltage and by a second transistor controlled by said first transistor for controlling re-firing of the power device in case of a negative pulse of the supply voltage during a quenching period of the power device, said monolithic integrated circuit including a substrate having a substrate surface forming a supply voltage terminal of said power device and having a substrate voltage, doped regions defined in the substrate to from active and passive components of the power device and the control device and a pocket formed in the substrate to surround at least said first transistor of the voltage limiting circuit of the control device, said pocket being biased at a voltage depending on that of said supply voltage terminal of the power device.
Claim 2
Dependent Claim
165 words
A monolithic integrated circuit including a power device for driving an inductive load and a control device for said power device, said control device comprising a voltage limiting circuit essentially constituted by a first transistor responsive to negative pulses of a supply voltage and by a second transistor controlled by said first transistor for controlling re-firing of the power device in case of a negative pulse of the supply voltage during a quenching period of the power device, said monolithic integrated circuit including a substrate having a substrate surface forming a supply voltage terminal of said power device and having a substrate voltage, doped regions defined in the substrate to from active and passive components of the power device and the control device and a pocket formed in the substrate to surround at least said first transistor of the voltage limiting circuit of the control device, said pocket being biased at a voltage depending on that of said supply voltage terminal of the power device.
Claim 3
Dependent Claim
12 words
The circuit of claim 1, wherein the pocket is an annular pocket.
Claim 4
Dependent Claim
153 words
A monolithic integrated circuit including a power device for driving an inductive load and a control device for said power device, said control device comprising a voltage limiting circuit essentially constituted by a first transistor responsive to negative pulses of a supply voltage and by a second transistor controlled by said first transistor for controlling re-firing of the power device in case of negative pulse of the supply voltage during a quenching period of the power device, said monolithic integrated circuit including a substrate having a substrate surface forming a supply voltage terminal of said power device and having a substrate voltage, doped regions defined in the substrate to form active and passive components of the power device and the control device and a pocket formed in the substrate to surround at least said first transistor of the voltage limiting circuit of the control device, said pocket being left at a floating potential.
Claim 5
Dependent Claim
153 words
A monolithic integrated circuit including a power device for driving an inductive load and a control device for said power device, said control device comprising a voltage limiting circuit essentially constituted by a first transistor responsive to negative pulses of a supply voltage and by a second transistor controlled by said first transistor for controlling re-firing of the power device in case of negative pulse of the supply voltage during a quenching period of the power device, said monolithic integrated circuit including a substrate having a substrate surface forming a supply voltage terminal of said power device and having a substrate voltage, doped regions defined in the substrate to form active and passive components of the power device and the control device and a pocket formed in the substrate to surround at least said first transistor of the voltage limiting circuit of the control device, said pocket being left at a floating potential.
Claim 6
Dependent Claim
12 words
The circuit of claim 3, wherein the pocket is an annular pocket.
Claim 7
Dependent Claim
174 words
A monolithic integrated circuit including a power device for driving an inductive load and a control device for said power device, said control device comprising a voltage limiting circuit essentially constituted by a first transistor responsive to negative pulses of a supply voltage and by a second transistor controlled by said first transistor for controlling re-firing of the power device in case of a negative pulse of the supply voltage during a quenching period of the power device, said monolithic integrated circuit including a substrate having a substrate surface forming a supply voltage terminal of said power device and having a substrate voltage, doped regions defined in the substrate to form active and passive components of the power device and the control device and a pocket formed in the substrate to contain therein at least a portion of at least said first transistor of the voltage limiting circuit of the control device, said pocket being surrounded by an area of different conductivity type which has a grounded contact distributed along an emerging portion thereof.
Claim 8
Dependent Claim
174 words
A monolithic integrated circuit including a power device for driving an inductive load and a control device for said power device, said control device comprising a voltage limiting circuit essentially constituted by a first transistor responsive to negative pulses of a supply voltage and by a second transistor controlled by said first transistor for controlling re-firing of the power device in case of a negative pulse of the supply voltage during a quenching period of the power device, said monolithic integrated circuit including a substrate having a substrate surface forming a supply voltage terminal of said power device and having a substrate voltage, doped regions defined in the substrate to form active and passive components of the power device and the control device and a pocket formed in the substrate to contain therein at least a portion of at least said first transistor of the voltage limiting circuit of the control device, said pocket being surrounded by an area of different conductivity type which has a grounded contact distributed along an emerging portion thereof.
Claim 9
Dependent Claim
12 words
The circuit of claim 5, wherein the pocket is an annular pocket.
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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) | 1995-07-21 | 1996-01-20 | 1996-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-21 | 2000-01-20 | 2000-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-21 | 2004-01-20 | 2004-07-21 | $7700.00 | Window Closed / Lapsed |