Power Supply with Digital Control Loop
AssigneeSilicon Laboratories Inc.
InventorsGeoffrey Thompson, Siddharth Sundar, Douglas R. Frey, Russell J. Apfel, Marius Goldenberg, Ion C. Tesu, Riad Wahby, Michael J. Mills
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Abstract
One embodiment of an apparatus for switching a transistor includes a first current mirror providing iB=K1i1, as a transistor base current, wherein the first current mirror is selectively driven by a current source i B MAX K 1 . A second current mirror providing a feedback signal i2=K2iD to the first current mirror such that i 1 + i 2 = i B MAX K 1 , wherein iD contributes to the transistor collector current, wherein iB=iBMAX−K1K2iD.
Claims9
An apparatus for switching a transistor:
- a first current mirror providing iB=K1i1, as a transistor base current, wherein the first current mirror is selectively driven by a current source
- i
- B
-
-
- MAX
- K
- 1
- ;
- a second current mirror providing a feedback signal i2=K2iD to the first current mirror such that
- i
- 1
- +
- i
- 2
- =
- i
- B
-
-
- MAX
- K
- 1
- ,
- wherein iD contributes to the transistor collector current, wherein iB=iBMAX−K1K2iD.
An apparatus for switching a transistor comprising:
- a first current mirror providing a base current iB=K1i1 to a transistor from a current source
- i
- B
-
-
- MAX
- K
- 1
- selectively coupled to the first current mirror;
- a second current mirror from which the transistor draws a portion iD of its collector current when a collector-to-emitter voltage of the transistor falls below a clamping point, wherein the second current source provides a feedback signal i2=K2iD to the first current source, wherein
- i
- 1
- +
- i
- 2
- =
- i
- B
-
-
- MAX
- K
- 1
- ,
- wherein iB=iBMAX−K1K2iD.
Dependencies are inferred from the claim text.