摘要 |
An output buffer circuit of a Pseudo Emitter Coupled Logic (PECL) uses a common level which is generated by a resistance division so that the common level is unstable to follow to a gradient of power source variation and an output signal level of the output buffer circuit is apt to be off from a level of the PECL. An output buffer circuit of PECL according to the present invention comprises: a first output terminal; a second output terminal; a first resistor connected between the first output terminal and a output terminal of a common level generator; a second resister connected between the second output terminal and the output terminal of the common level generator; and a driver circuit which makes a current from the first output terminal to the second output terminal through the first resistor and second resistor when a first input signal and a second input signal complementary to the first input signal result a first data, and makes a current from the second output terminal to the first output terminal through the second resistor and the first resistor when the first input signal and the second input signal result a second data; a common level which follows its fluctuation to that of power source is supplied to the connecting point of the first and second resistors.
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