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US5377094A Expired / Lapsed US ⏱️ 0.0 years remaining

Push-pull output stage for driving motors which generates auxiliary voltage supply

Assignee: Vishay Siliconix Inc
•
Filing: 1993-05-14
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Granted: 1994-12-27
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Expires: 2013-05-14
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Abstract

Abstract A push-pull output stage for driving a motor which provides an auxiliary power supply Vaux above supply voltage Vcc by using highside MOSFETs which do not have source-body shorts, and by connecting a capacitor to the poles of the motor through rectifying diodes which output flyback pulses to the capacitor. Damage to the highside MOSFETs is prevented by limiting the voltage on the capacitor using a zener diode. The push-pull output stage increases the driving potential applied to the motor be eliminating the need for an isolating Schottky diode between the output stage and a power source. Back emf continues to supply energy to Vaux even after Vcc is removed.

Inventors

  • 👤 Richard K. Williams
  • 👤 Allen A. Chang
  • 👤 Barry J. Concklin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 02:33
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/33561; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5387; H02P; H02P5/00; H02P7/00; H02P7/03; H02P7/04; H02M1/00; H02M1/0003; H02M1/0006; H02M3/02; H02M3/04; H02M3/10; H02M3/145; H02M3/155; H02M3/1555

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 73 words
A push-pull output stage for driving a motor comprising: a first MOSFET including a first drain connected to a power supply, a first source, and a body electrically isolated from said first source; a second MOSFET including a grounded second source and a second drain; said motor having a pole connected to the first source and the second drain; and a charge storing device connected to the first source and the second drain.
Claim 2
Dependent Claim 73 words
A push-pull output stage for driving a motor comprising: a first MOSFET including a first drain connected to a power supply, a first source, and a body electrically isolated from said first source; a second MOSFET including a grounded second source and a second drain; said motor having a pole connected to the first source and the second drain; and a charge storing device connected to the first source and the second drain.
Claim 3
Dependent Claim 74 words
An output stage according to claim 1, wherein said first MOSFET is an n-channel MOSFET, said second MOSFET is an n-channel MOSFET, and said output stage further comprises: an asymmetric element connected between the charge storing device and the first source and the second drain, said asymmetrical element allowing charge to accumulate on said charge storing device, but preventing current flow from said charge storing device to said first source and said second drain.
Claim 4
Dependent Claim 35 words
An output stage according to claim 2, wherein said asymmetric element is a diode having an anode connected to said first source and said second drain, and a cathode connected to said charge storing device.
Claim 5
Dependent Claim 13 words
An output stage of claim 1 wherein said body is connected to ground.
Claim 6
Dependent Claim 16 words
An output stage of claim 1 wherein said body is maintained at a predetermined voltage level.
Claim 7
Dependent Claim 31 words
An output stage of claim 1 wherein said charge storing device is a grounded capacitor and said output stage further comprises a grounded zener diode connected in parallel with the capacitor.
Claim 8
Dependent Claim 46 words
An output stage of claim 1, wherein said first and second MOSFETs form a halfbridge and said motor has a plurality of windings, and wherein said output stage further comprises a plurality of identical halfbridges, each halfbridge being connected to one of said plurality of windings.
Claim 9
Dependent Claim 13 words
An output stage of claim 7, wherein said number of windings is three.
Claim 10
Dependent Claim 74 words
A push-pull output stage for driving a motor comprising: a first MOSFET including a first source connected to a power supply, a first body electrically isolated from said first source, and a first drain; a second MOSFET including a grounded second source, a grounded second body, and a second drain; said motor having a pole connected to the first drain and the second drain; and a charge storing device connected to the first body.
Claim 11
Dependent Claim 74 words
A push-pull output stage for driving a motor comprising: a first MOSFET including a first source connected to a power supply, a first body electrically isolated from said first source, and a first drain; a second MOSFET including a grounded second source, a grounded second body, and a second drain; said motor having a pole connected to the first drain and the second drain; and a charge storing device connected to the first body.
Claim 12
Dependent Claim 22 words
An output stage of claim 9, wherein said first MOSFET is a p-channel MOSFET and said second MOSFET is an n-channel MOSFET.
Claim 13
Dependent Claim 31 words
An output stage of claim 9 wherein said charge storing device is a grounded capacitor and said output stage further comprises a grounded zener diode connected in parallel with the capacitor.
Claim 14
Dependent Claim 50 words
An output stage of claim 9 wherein said first and second MOSFETs form a halfbridge and said motor comprising a plurality of windings, and wherein said output stage further comprises a plurality of identical halfbridges, each of said plurality of halfbridges being connected to one of said plurality of windings.
Claim 15
Dependent Claim 13 words
An output stage of claim 12, wherein said number of windings is three.
Claim 16
Independent Claim 107 words
A method for recovering flyback energy from a motor which is connected to a push-pull output stage comprised of an n-channel highside MOSFET and an n-channel lowside MOSFET, wherein a first source of the highside MOSFET is electrically separated from a first body of the highside MOSFET, the method comprising the steps of: connecting a first drain of the highside MOSFET to a supply voltage; connecting said first body of the highside MOSFET to ground; connecting a second source of the lowside MOSFET to ground; and connecting a charge storing device to the first source of the highside MOSFET and a second drain of the lowside MOSFET.
Claim 17
Independent Claim 107 words
A method for recovering flyback energy from a motor which is connected to a push-pull output stage comprised of an n-channel highside MOSFET and an n-channel lowside MOSFET, wherein a first source of the highside MOSFET is electrically separated from a first body of the highside MOSFET, the method comprising the steps of: connecting a first drain of the highside MOSFET to a supply voltage; connecting said first body of the highside MOSFET to ground; connecting a second source of the lowside MOSFET to ground; and connecting a charge storing device to the first source of the highside MOSFET and a second drain of the lowside MOSFET.
Claim 18
Dependent Claim 72 words
A method of claim 14 further comprising the step of: connecting a diode between the charge storing device and the first source of the highside MOSFET and the second drain of the lowside MOSFET such that an anode of the diode is connected to the first source of the highside MOSFET and the second drain of the lowside MOSFET and a cathode of the diode is connected to the charge storing device.
Claim 19
Dependent Claim 39 words
A method of claim 14 further comprising the step of: connecting a grounded zener diode in parallel with the charge storing device such that voltage potentials greater than the capacity of the charge storing device are shunted to ground.

References Cited (Backward Citations)

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US4829415A Cited
US4901216A Cited
US5019719A Cited
US5119000A Cited
US5262704A Cited
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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) 1997-12-26 1998-06-27 1998-12-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-12-26 2002-06-27 2002-12-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-12-26 2006-06-27 2006-12-27 $7700.00 Window Closed / Lapsed

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