Other Parts Discussed in Thread: SN74AHCT125
SN74AHC32PWR的输出接SN74AHCT125PWR的使能脚,控制SN74AHCT125PWR的通断,SN74AHCT125PWR的是否还要接上拉电阻?
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SN74AHC32PWR的输出接SN74AHCT125PWR的使能脚,控制SN74AHCT125PWR的通断,SN74AHCT125PWR的是否还要接上拉电阻?
您好,
为了确保上电和掉电期间输出高阻态,SN74AHCT125的OE是需要通过上拉电阻连接到VCC的,datasheet有描述“To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.”
看下面SN74AHCT125真值表,OE高电平时,其输出高组态,因此是不需要的