Title:
INTERNAL STEP-DOWN POWER SUPPLY CIRCUIT
Document Type and Number:
Japanese Patent JP3561158
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an internal step-down power supply circuit with a high load current ability without increasing the layout area and current consumption.
SOLUTION: A potential difference detecting circuit 13 detects the potential difference between a reference voltage VREF and an internal step-down power supply voltage VINT and amplifies that potential difference. A cross coupling type amplifier circuit 14 inputs two outputs of an amplified output VDRV2 of the potential difference detecting circuit 13 and of an output VDRV of a current mirror type differential amplifier circuit 11. The control voltage VDRV to a P channel MOSFET driving circuit 12 is provided with an amplitude of almost equal to potential width &verbar VDD-VSS&verbar of an external power supply voltage by the operation of the cross coupling type amplifier circuit 14 and the P channel MOSFET driving circuit 12 has the high load current ability. On the condition that a load current IROAD is a little, a control signal generating circuit 15 prevents the useless increase of current consumption by stopping the operation of the said potential difference detecting circuit 13 and cross coupling type amplifier circuit 14.
Inventors:
Satoshi Takashima
Makoto Kojima
Makoto Kojima
Application Number:
JP26627698A
Publication Date:
September 02, 2004
Filing Date:
September 21, 1998
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G05F1/46; G05F1/56; G11C11/407; G11C11/413; (IPC1-7): G05F1/56; G11C11/407; G11C11/413
Domestic Patent References:
| JP5011866A | ||||
| JP7162248A | ||||
| JP57025711A |
Attorney, Agent or Firm:
Hiroshi Maeda
Hiroshi Koyama
Ichiro Oneda
Hiroshi Koyama
Ichiro Oneda
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