发明名称 Apparatus and method for dual features of frequency setting and frequency synchronization in one pin
摘要 An integrated circuit includes an oscillator circuit, where a frequency of an oscillator output signal provided by the oscillator circuit is adjustable by either coupling a resistor to an input pin, or by applying an external clock signal to the input pin. The oscillator circuit includes a comparator, a follower, a current-controlled oscillator, and a switch circuit. The switch circuit is coupled between the input pin and a node that is coupled to the current-controlled oscillator. Also, the follower is arranged to cause the voltage at the node to be at a pre-defined voltage unless the voltage at the node is overdriven by an external clock signal. The comparator circuit is arranged to determine whether the signal at the input pin is a clock signal. If it is determined that the signal at the input pin is a clock signal, the switch circuit is opened.
申请公布号 US7196589(B1) 申请公布日期 2007.03.27
申请号 US20040971502 申请日期 2004.10.21
申请人 NATIONAL SEMICONDUCTOR CORPORATION 发明人 SILVA FARUK JOSE NOME;CHIU KWOK-FU
分类号 H03B5/24;H03K3/02 主分类号 H03B5/24
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