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United States Patent | 5,646,579 |
Blodgett | July 8, 1997 |
A temperature sensitive oscillator circuit and control circuit which together form a current source. The temperature sensitive oscillator circuit generates an output signal which controls a frequency of a refresh oscillator circuit. The duty cycle of the output signal of the temperature sensitive oscillator circuit is temperature dependent and increases for increases in temperature. The output signal of the temperature sensitive oscillator circuit controls the control circuit which sources current between the refresh oscillator circuit and a supply node. As the duty cycle of the output signal of the temperature sensitive oscillator circuit increases a time duration during which the control circuit sources current between the refresh oscillator circuit and the supply node increases. This increase increases the frequency of the output signal of the refresh oscillator circuit. The output signal of the refresh oscillator circuit is an internal clock signal which controls a refresh cycle of a memory circuit.
Inventors: | Blodgett; Greg A. (Boise, ID) |
Assignee: | Micron Technology, Inc. (Boise, ID) |
Appl. No.: | 504939 |
Filed: | July 20, 1995 |
Intern'l Class: | H03B 005/02; H03K 003/023.1 |
Field of Search: | 331/47,57,66,74,75,111,176 365/222 |
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5465063 | Nov., 1995 | Fukuda et al. | |
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Foreign Patent Documents | |||
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