Title:
POWER SUPPLY UNIT AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME
Document Type and Number:
Japanese Patent JP3732173
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a power supply unit for generating stable output voltage at a low cost even if an abrupt load change occurs.
SOLUTION: This power supply unit comprises a sense resistor Rs for monitoring an output current Io disposed more downstream than output smoothing parts (L1, D1 and Co) for smoothing the terminal voltage of an FETQ1. A driver which controls the driving of the FETQ1 comprises an error amplifier A1 of generating an error voltage Vc between a first reference voltage Vb and a reference voltage Va corresponding to an output voltage Vo, a comparator CMP of generating a comparison signal Ve between a second reference voltage Vd and the error voltage Vc corresponding to an inductor current IL, driving signal generating parts (LC, BUF) of generating a driving signal of the FETQ1 corresponding to the comparison signal Ve, and an off-set parts (A2, E2) of giving the off-set corresponding to a monitor result of the sense resistance Rs to the second reference voltage Vd prior to inputting into the comparator CMP.
Inventors:
Kenichi Nakata
Application Number:
JP2002333550A
Publication Date:
January 05, 2006
Filing Date:
November 18, 2002
Export Citation:
Assignee:
ROHM Co., Ltd.
International Classes:
G09G3/36; H02M3/155; G05F1/56; G09G3/20; H02M3/156; (IPC1-7): H02M3/155; G09G3/20; G09G3/36
Domestic Patent References:
| JP2002281742A | ||||
| JP2001112250A | ||||
| JP2000299981A | ||||
| JP11136938A | ||||
| JP9093912A |
Attorney, Agent or Firm:
Shizuo Sano