Adaptive threshold of a zero crossing comparator
First Claim
Patent Images
1. A buck converter device comprising:
- a high-side switch device with a first parasitic bipolar junction transistor configured to provide a first sense signal depending from a current flowing through the first parasitic bipolar junction transistor to a zero-cross comparator;
a low-side switch device with a second parasitic bipolar junction transistor configured to provide a second sense signal depending from current flowing through the second parasitic bipolar junction transistor to the zero-cross comparator;
a sense capacitive element, wherein a first terminal of the sense capacitive element is connected to ground and a second terminal of the sense capacitive element is connected to the zero-cross comparator, directly connected to a collector of the first parasitic bipolar junction transistor and directly connected to a collector of the second parasitic bipolar junction transistor, wherein the sense capacitive element is configured to provide an offset adjustment from said first and second sense signals combined to the zero-cross comparator; and
the zero-cross comparator with an adaptive threshold configured with the offset adjustment provided from said first sense signal and said second sense signal combined via said sense capacitive element.
2 Assignments
0 Petitions
Accused Products
Abstract
A buck converter device with a zero-cross comparator with an adaptive threshold. The buck converter comprises of a control block that controls a first p-channel MOSFET switch, and a second n-channel MOSFET switch. The p-channel MOSFET switch and the n-channel MOSFET switch provide a sense signal utilizing parasitic bipolar junction transistors. The p-channel MOSFET provides a sense current for the pnp parasitic bipolar junction transistor, The n-channel MOSFET provides a sense current for the npn parasitic bipolar junction transistor. The sense current is stored on a capacitor, and establishes an adaptive offset adjustment to a zero-cross comparator.
14 Citations
27 Claims
-
1. A buck converter device comprising:
-
a high-side switch device with a first parasitic bipolar junction transistor configured to provide a first sense signal depending from a current flowing through the first parasitic bipolar junction transistor to a zero-cross comparator; a low-side switch device with a second parasitic bipolar junction transistor configured to provide a second sense signal depending from current flowing through the second parasitic bipolar junction transistor to the zero-cross comparator; a sense capacitive element, wherein a first terminal of the sense capacitive element is connected to ground and a second terminal of the sense capacitive element is connected to the zero-cross comparator, directly connected to a collector of the first parasitic bipolar junction transistor and directly connected to a collector of the second parasitic bipolar junction transistor, wherein the sense capacitive element is configured to provide an offset adjustment from said first and second sense signals combined to the zero-cross comparator; and the zero-cross comparator with an adaptive threshold configured with the offset adjustment provided from said first sense signal and said second sense signal combined via said sense capacitive element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A voltage converter device comprising:
-
a high-side switch device with a first parasitic bipolar junction transistor configured to provide a first sense signal depending from a current flowing through the first parasitic bipolar junction transistor to a zero-cross comparator; a low-side switch device with a second parasitic bipolar junction transistor configured to provide a second sense signal depending from a current flowing through the second parasitic bipolar junction transistor to the zero-cross comparator; a sense capacitive element configured to provide charge storage for said first sense signal, and said second sense signal, wherein a first terminal of the sense capacitive element is connected to ground and a second terminal of the sense capacitive element is connected to the zero-cross comparator, directly connected to a collector of the first parasitic bipolar junction transistor and directly connected to a collector of the second parasitic bipolar junction transistor, and to a collector of the second parasitic bipolar junction transistor, wherein the sense capacitive element is configured to provide an offset adjustment from said first and second sense signals combined to the zero-cross comparator; the zero-cross comparator with an adaptive threshold whose first and second input are electrically connected to a drain and a source of said low-side switch device; a feedback loop electrically connected to said capacitive element configured to provide the offset adjustment for said zero-cross comparator; and
,a control block configured to provide electrical controls for said high-side switch device and said low-side switch device. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
-
17. A method of adaptive threshold control for a zero-cross comparator comprising the steps:
-
providing a buck converter comprising a high-side MOSFET switch with a first parasitic bipolar transistor, wherein a collector of the first parasitic bipolar transistor is directly connected to a second terminal of a sense capacitive element, a low-side MOSFET switch with a second parasitic bipolar transistor, a sense capacitive element, wherein a collector of the second parasitic bipolar transistor is directly connected to the second terminal of the sense capacitive element, the zero-cross comparator, an offset adjustment feedback loop, a control block, an inductor, and an output capacitor; sensing a first sense signal from said first parasitic bipolar transistor depending from a current flowing through the first parasitic bipolar transistor to the zero-cross comparator via said sense capacitive element; sensing a second sense signal from said second parasitic bipolar transistor depending from a current flowing through the second parasitic bipolar transistor to the zero-cross comparator via said sense capacitive element; storing a combination of the first signal and the second signal on said sense capacitive element; providing the combination of the first and the second sense signal to said offset adjustment feedback loop; adjusting a zero-cross comparator response depending on said combination of the first and said second sense signals; generating an output signal from said zero-cross comparator to said control block. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
Specification