Semiconductor integrated circuit device having an internally produced operation voltage matched to operation speed of circuit
AssigneesHitachi, Ltd., Hitachi Microcomputer System Ltd.
InventorsAkira Uchiyama, Ryuji Shibata, Yoshinobu Nakagome, Masaharu Kubo
Life of this patent
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Abstract
The semiconductor integrated circuit device incorporates a power supply circuit which forms an operation voltage that matches the operation speed of the internal circuit. Since the operation voltage is set in accordance with the operation speed required of the internal circuit, the internal circuit can be operated with a minimum required voltage even when there are process variations and temperature changes. In other words, a rational power supply is realized.
Claims9
A semiconductor integrated circuit device formed on a single semiconductor chip, comprising:
- an external power supply terminal connected with a battery as an external power supply;
- an internal circuit including a plurality of MOSFETs;
- and
- an internal power supply means connected to said external power supply terminal and providing on the basis of said external power supply an operation voltage to be supplied to said internal circuit,
- wherein said internal power supply means includes:
- detection means connected to said external power supply terminal to detect a voltage of said battery;
- voltage conversion means to selectively perform a step-up or step-down operation on the battery voltage, said voltage conversion means including a selection function to select one of the step-up and step-down operations according to a detection signal outputted from said detection means and a conversion execution function to execute a selected operation in response to a clock signal;
- supply means to supply as the operation voltage to said internal circuit a voltage which is responsive to a voltage outputted from said voltage conversion means;
- clock signal generation means to form said clock signal supplied to said voltage conversion means;
- and
- control means connected to said clock signal generation means to control a frequency of the generated clock signal so that the operation voltage outputted from said supply means conforms to an internal power supply voltage for achieving an operation speed required of said internal circuit.
Dependencies are inferred from the claim text.