SN74AVC4T245: Application Usage Consult

Stanley Dai

Part Number: SN74AVC4T245

Hi Team,

Customer has two questions for our SN74AVC4T245, pls kindly help us here.

1. Our D/S recommends connect OE1 and OE2 with VCC pin for keeping port under high impedance state, is it okay to pull OE1 and OE2 w/ GND for always enabling channels?

2. How to select the suitable pull-up resistor for OE1 and OE2 pin w/ VCC in application?

Best,

Stanley

over 1 year ago

+1 Clemens Ladisch over 1 year ago

Guru 243820 points

The datasheet says:

To ensure the high-impedance state during power up or power down, /OE should be tied to V_CC through a pullup resistor.

If you do not care about the state during power up or power down, you can tie it directly to GND.

0 Stanley Dai over 1 year ago in reply to Clemens Ladisch

TI__Expert 5810 points

Hi Clemens,

Thanks for help. Do you know how to select suitable pull-up resistor value when tie /OE to Vcc here?

+1 Clemens Ladisch over 1 year ago in reply to Stanley Dai

Guru 243820 points

See Choosing an Appropriate Pull-up/Pull-down Resistor. But this gives you a wide range; 10 kΩ is common, or more if you need to save power.

Logic

Logic forum

SN74AVC4T245: Application Usage Consult