| 摘要 |
PURPOSE:To change a voltage standard of an input/output logical level by providing a programmable element connected in series with an internal temperature compensation circuit and using an external write current to connect/ disconnect the said circuit. CONSTITUTION:Diodes DP and DT1 as program element and program current path are added to an output circuit. Since an external terminal VCC is at the highest potential, the element DT1 is turned on at program and flows a program current. A voltage difference between points E and F of collectors of Trs Q1 and Q2 is 0.6-1.1V from the voltage difference between high and low potentials in a characteristic in figure, and it is lower than the two stages' share of the voltage VF required to turn on the element DP, then the DP is always turned off. Thus, the temperature compensation circuit X specific to '100K interface' is disconnected and '10K interface' is formed. Further, a program current of 40mA flows from an output terminal OUT to the power terminal VCC to destroy the DP junction to form the '100K interface'. Then the interface change is attained after the end of assembling.
|
