Title:
OVERCURRENT PROTECTION CIRCUIT
Document Type and Number:
Japanese Patent JP2018026963
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To ensure both momentary current securing and safety improvement.SOLUTION: An overcurrent protection circuit 71 has a current control section 110 for controlling conductivity of a transistor so as to limit an output current, flowing while the transistor is turned ON, below a predetermined upper limit value, and a duty control section 120 starting to turn the transistor ON/OFF forcibly at a predetermined duty ratio Don, when a temperature protection circuit detects temperature abnormality (S73=H) in a state where the current control section 110 is limiting the output current (S110=H). The current control section 110 compares a sense voltage Vs according to the output current with a threshold voltage according to the upper limit value, and generates a first overcurrent protection signal S71a for controlling the conductivity of the transistor, and a state notification signal S110 for notifying the duty control section 120 of the state that itself is limiting the output current.SELECTED DRAWING: Figure 5
Inventors:
TAKUMA TORU
TAKAHASHI SHUNTARO
TAKAHASHI NAOKI
TAKAHASHI SHUNTARO
TAKAHASHI NAOKI
Application Number:
JP2016157832A
Publication Date:
February 15, 2018
Filing Date:
August 10, 2016
Export Citation:
Assignee:
ROHM CO LTD
International Classes:
H02H3/087; H02H5/04; H02H7/20
Domestic Patent References:
| JP2015213404A | 2015-11-26 | |||
| JPH04169915A | 1992-06-17 | |||
| JP2015057017A | 2015-03-23 | |||
| JP2012090214A | 2012-05-10 | |||
| JP2011061948A | 2011-03-24 |
Foreign References:
| US6867573B1 | 2005-03-15 |
Attorney, Agent or Firm:
Sano patent office
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