Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

TXB0108 Logic Translator Problem: Low output

Status
Not open for further replies.

thobson

Newbie level 1
Joined
Feb 1, 2013
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,290
Hi,

I'm trying to use a TXB0108 (www.ti.com/lit/ds/symlink/txb0108.pdf) bidirectional logic translator to convert 5V to 3.3V and vice versa. When I send a 5Vpp time-varying digital input (like a square wave) to the 5V side, I don't get the same signal at 3.3Vpp on the output side. What I get is a signal that toggles with the input, but is only ~25mVpp centered around ~1.5V. However, the chip has no problem converting DC voltages up/down. Only when the signal toggles do I get this odd behaviour.

The settings are: Vcca=3.3V, Vccb = 5V, OE = 3.3V.

I've read that a load on the output of this chip can cause problems, but there isn't much of a load on the output, and I get the same behaviour using a completely disconnected/unloaded output.

Could this be a sign that the part is damaged, or might there be some other problem?

Thanks!
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top