US 7,498,865 B2
Semiconductor integrated circuit with reduced speed variations
Shiro Sakiyama, Yawata (Japan); Masayoshi Kinoshita, Settsu (Japan); and Masaya Sumita, Amagasaki (Japan)
Assigned to Panasonic Corporation, Osaka (Japan)
Appl. No. 10/511,165
PCT Filed Feb. 19, 2004, PCT No. PCT/JP2004/001942
§ 371(c)(1), (2), (4) Date Oct. 14, 2004,
PCT Pub. No. WO2004/077673, PCT Pub. Date Oct. 09, 2004.
Claims priority of application No. 2003-047418 (JP), filed on Feb. 25, 2003.
Prior Publication US 2005/0162212 A1, Jul. 28, 2005
Int. Cl. H03K 3/01 (2006.01)
U.S. Cl. 327—534  [327/535] 5 Claims
OG exemplary drawing
 
1. A semiconductor integrated circuit, comprising:
a main circuit including a plurality of MOS transistors in which a source potential and a substrate potential are separated from each other, and operating while receiving an operating power supply voltage; and
a substrate potential control circuit for controlling the substrate potential of a MOS transistor in the main circuit so that a saturation current value of the MOS transistor is equal to a target saturation current value, the substrate potential control circuit, including:
a constant current generation circuit;
a current-voltage conversion circuit including a MOS transistor provided therein and having current-voltage conversion characteristics that change according to the substrate potential of the MOS transistor provided therein for converting a constant current value of the constant current generation circuit to a voltage value; and
a differential amplifier circuit comparing the voltage value generated by the current-voltage conversion circuit with the operating power supply voltage and outputting a voltage for controlling the substrate potential of the current-voltage conversion circuit so that the voltage value generated by the current-voltage conversion circuit is equal to the operating power supply voltage value of the main circuit,
wherein the substrate potential control circuit controls a substrate potential of a MOS transistor in the main circuit, and
the constant current generation circuit generates a plurality of constant current values, and selectively outputs one of the plurality of constant current values.