SN74HCT574: initial output

Youwei Song

Part Number: SN74HCT574

Customer test NXP's 74HCT574PW, 118 and TI's SN74HCT574PW and found that the initial output level of power-on is not the same as that of power-on, everything is normal

3 个月前

0 Alice 3 个月前

TI__Genius 15240 points

Hello ,

We do not familiar with NXP chip, please describe your issue about SN74HCT574 data sheet, product information and support | TI.com.

0 Youwei Song 3 个月前

TI__Prodigy 10 points

The customer connects the OE pin to ground, the output Q level is high at the initial moment of power-up, and the output level becomes low after the program is initialized, how can the output be guaranteed to be low at the initial moment?

0 Alice 3 个月前回复 Youwei Song

TI__Genius 15240 points

Hello，

Regarding “Table 6-1. Function Table”， it is hard to guarantee if OE is enabled all the time.

Or you may try to connect a pull down resistor in output pin .

0 Youwei Song 2 个月前回复 Alice

TI__Prodigy 10 points

What is different between OUTPUT Q0 & Z? The customer connects the OE pin to ground, the output Q level is high at the initial moment of power-up, and the output level becomes low after the program is initialized, how can the output be guaranteed to be low at the initial moment? (can't add pull-down resistor)

0 Alice 2 个月前回复 Youwei Song

TI__Genius 15240 points

Hello ,

Z means HI-Z, Q0 means previous output.

We suggest you use pull-down resistor to guarantee initial low if OE is enabled when power up.

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SN74HCT574: initial output