Claims
- 1. A semiconductor integrated circuit device comprising:a supply voltage terminal; analog circuits connected to said supply voltage terminal; a regulator circuit having an input connected to said supply voltage terminal and outputting an output voltage that is varied by a signal supplied via an adjustment terminal and lower than said supply voltage; and digital circuits connected to an output of said regulator circuit, wherein the output voltage of said regulator circuit is so low that noise occurring in the digital circuits is minimized and wherein the regulator circuit further isolates said analog and digital circuits such that noise occurring in the digital circuits does not affect the analog circuits electrically connected to the supply voltage terminal.
- 2. A semiconductor integrated circuit device comprising:a supply voltage terminal; analog circuits connected to said supply voltage terminal; a regulator circuit having an input connected to said supply voltage terminal and outputting an output voltage that is varied by a signal supplied via an adjustment terminal and lower than said supply voltage; and digital circuits connected to an output of said regulator circuit so that noise occurring in the digital circuits is shut out by the regulator circuit so as not to affect the analog circuits electrically connected to the supply voltage terminal, wherein said regulator circuit comprises: a differential amplifier; a reference voltage generating circuit for supplying a reference voltage to a first input terminal of said differential amplifier; an emitter follower for feeding an output of said differential amplifier to an output terminal; a first and second resistor connected in series between said output terminal and ground; a conductor for connecting a node between said first and second resistors to a second input terminal of said differential amplifier; a plurality of resistors connected in parallel with said first resistor between said output terminal and said node; and means for determining which one or ones of said plurality of resistors to bring into an active state.
- 3. A semiconductor integrated circuit device comprising:a supply voltage terminal; analog circuits connected to said supply voltage terminal; a regulator circuit having an input connected to said supply voltage terminal and outputting an output voltage that is varied by a signal supplied via an adjustment terminal and lower than said supply voltage; and digital circuits connected to an output of said regulator circuit so that noise occurring in the digital circuits is shut out by the regulator circuit so as not to affect the analog circuits electrically connected to the supply voltage terminal, wherein said regulator circuit comprises: a differential amplifier; a reference voltage generating circuit for supplying a reference voltage to a first input terminal of said differential amplifier; an emitter follower for feeding an output of said differential amplifier to an output terminal; a first and a second resistor connected in series between said output terminal and ground; a conductor for connecting a node between said first and second resistors to a second input terminal of said differential amplifier; and a plurality of pairs of switching device and a resistor connected between said output terminal and said node, wherein the switching devices included in said plurality of pairs of switching device and a resistor are controlled by a signal fed thereto via said output voltage adjustment terminal so as to vary a resistance between said node and said output terminal and thereby vary a voltage appearing at said output terminal.
- 4. A semiconductor integrated circuit device comprising:a supply voltage terminal; analog circuits connected to said supply voltage terminal; a regulator circuit having an input connected to said supply voltage terminal and outputting an output voltage that is lower than said supply voltage and said output voltage becomes higher when temperature rises and becomes lower when temperature drops; and digital circuits connected to an output of said regulator circuit, wherein the output voltage of said regulator circuit is so low that noise occurring in the digital circuits is minimized and wherein the regulator circuit further isolates said analog and digital circuits such that noise occurring in the digital circuits does not affect the analog circuits electrically connected to the supply voltage terminal.
- 5. The semiconductor integrated circuit device of claim 1, wherein the output voltage of said regulator circuit is varied in steps.
Priority Claims (2)
Number |
Date |
Country |
Kind |
10-30719 |
Feb 1998 |
JP |
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10-30720 |
Feb 1998 |
JP |
|
Parent Case Info
This is a Continuation of application Ser. No. 09/249,120 filed Feb. 12, 1999 now U.S. Pat. No. 6,268,763. The disclosure of the prior application is hereby incorporated by reference herein in its entirety.
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
Country |
Parent |
09/249120 |
Feb 1999 |
US |
Child |
09/783583 |
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US |