SN74LVC8T245-Q1: Using DIR pin for controlling the output

Prachi Moghe

Part Number: SN74LVC8T245-Q1
Other Parts Discussed in Thread: SN74LVC2T45-Q1

Hi Team,

I am using SN74LVC8T245-Q1 8-bit dual supply bus transceiver to interface serial flash (3.3V logic) to controller at 5V supply.

The device SN74LVC8T245-Q1 has direction-control (DIR) input & Output Enable (OE#) input to enable either of the output ports, i.e., A or B.

1. Please elaborate how these pins work/ share application note if available.

2. Is it possible to use few of the A port pins as input & the remaining as output with the same device? same with the port B.

Thanks,

Prachi

over 5 years ago

0 Clemens Ladisch over 5 years ago

Guru 266850 points

See the logic diagram on page 2 of the datasheet.

The OE pin disables all output drivers. The DIR pin disables the output drivers on one side. The input buffers are always active, and must always have a valid logic level.

There is only a single DIR pin for all channels. If you need both directions at the same time, use multiple chips.

0 ShreyasRao over 5 years ago

TI__Guru 57340 points

Hi Prachi,

2) You can also consider using multiple SN74LVC2T45-Q1 device if you need few A to B and few B to A channel control.

Refer to this app note on the LVCxT devices:
www.ti.com/.../slva746.pdf

Logic

Logic forum

SN74LVC8T245-Q1: Using DIR pin for controlling the output