发明名称 |
OSCILLATOR AMPLIFIER WITH INPUT CLOCK DETECTION AND METHOD THEREFOR |
摘要 |
An oscillator circuit has a crystal oscillator amplifier having only two clock input terminals, one being an input terminal and the other being an output terminal. The input terminal allows a user of the integrated circuit to choose between connecting a first clock signal generated from a crystal or a second clock signal generated by a non-crystal source to the input terminal. Control circuitry has a capacitor coupled in parallel with a transistor. Both are coupled in series with a resistive device at an output of the control circuitry to provide a control signal. Clock generation circuitry coupled to the crystal oscillator amplifier provides an oscillating output signal in response to an enable signal. In one form a comparator circuit provides the oscillating output signal. The control signal is used to ensure that inputs to the comparator circuit repeatedly cross each other over time.
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申请公布号 |
US2011037524(A1) |
申请公布日期 |
2011.02.17 |
申请号 |
US20090541704 |
申请日期 |
2009.08.14 |
申请人 |
DAO CHRIS C;PIETRI STEFANO;ZHANG WENZHONG |
发明人 |
DAO CHRIS C.;PIETRI STEFANO;ZHANG WENZHONG |
分类号 |
H03L7/00 |
主分类号 |
H03L7/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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