Switching element and protection circuit using the same
AssigneeSanyo Electric Co., Ltd.
InventorTadao Mandai
Life of this patent
Estimating the term…
Abstract
Provided is a switching element including: first switching element primarily used for formation of a two-way current path; a second switching element that forms, at the time when the first switching element is turned off, a current path by switching a parasitic diode from another; and a third switching element. The second and third switching elements may be of smaller chip size because they allow a current to flow through them only while the current path of the first switching element is being switched. This contributes miniaturization of the switching element as well as reduction in the ON resistance. Moreover, adoption of the switching element to a protection circuit realizes miniaturization of the protection circuit.
Claims11
A switching device comprising:
- a first switching element, a second switching element and a third switching element, each of the switching elements comprising a control terminal, a first power terminal, a second power terminal and a back gate,
- wherein the first power terminal of the second switching element is connected with the first power terminal of the first switching element, and the second power terminal of the second switching element is connected with the back gates of the first and second switching elements, and
- the first power terminal of third switching element is connected with the second power terminal of the first switching element, and the second power terminal of the third switching element is connected with the back gates of the first and third switching elements.
A protection circuit for a secondary battery, comprising:
- a switching device comprising a first switching element, a second switching element and a third switching element, the first switching element being connected with the secondary battery in series, the second switching element being connected with the third switching element in series, and the connected second and third switching elements as a whole being connected with the first switching element in parallel;
- and
- a control device controlling the first, second and third switching elements so that the secondary battery is charged when a current flows in a first direction through the switching device and the secondary battery is discharged when a current flows in a second direction through the switching device.
Dependencies are inferred from the claim text.