| 摘要 |
PURPOSE: A method of controlling programmable impedance of semiconductor apparatus and a circuit of producing the output thereof are provided to produce stable impedance matching regardless of other conditions CONSTITUTION: A circuit of producing programmable impedance control signal includes two sections of impedance detection, comparison and co-ordination(200,250,300,350,351,400,401), and of driving and data output. The first section compares a pad voltage(XZQ) of a pad connected to an external resistor(RZQ) and an array reference voltage(REFIO) and conducts a normal compensation by tracking the pad voltage(XZQ) after the array reference voltage(REFIO). The first section also compares between a reference voltage(REF) decided by a voltage divider by resistance(DIV) and the array reference voltage(REFIO) or the pad voltage((XZQ) and conducts an automatic compensation by tracking the array reference voltage(REFIO) or the pad voltage(XZQ) after the reference voltage(REF). The section of driving and data output, then, conducts an impedance driving of the data output section(DQ) of the semiconductor device corresponding to the results of the normal and automatic compensation and sends out the internal data.
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