TXB0302: VIH and VIL inquire

Tommy Tzeng

Genius 5895 points

Part Number: TXB0302

Hi Sir,

the customer test condition as follows:

1.VCCA=3.3V/ VCCB=1.8V

2.A1 use a signal generator to 3.3v and 0v 13Mhz periodic square waveform, and measure the B1 waveform.

test A1 vin high is adjusted to about 1.3v, the B1 level signal will be to low , and there is a gap between VIH=VCCI * 0.65= 3.3 * 0.65=2.145v in the datasheet. is this test method wrong? looking forward to your reply and suggesion.

over 4 years ago

0 Emrys Maier over 4 years ago

TI__Guru* 97066 points

Hello,

Today is a US holiday - we will get back to you when we return to the office tomorrow.

0 Dylan Hubbard over 4 years ago

TI__Mastermind 46395 points

Hey Tommy,

What exactly is the question? Are you asking why 1.3 V at the input still results in a Low at the output? If so, this FAQ may help.

0 Tommy Tzeng over 4 years ago in reply to Dylan Hubbard

Genius 5895 points

Hi Sir,

sorry~waiting for customer waveform will better explain the customer problem.

0 Tommy Tzeng over 4 years ago in reply to Dylan Hubbard

Genius 5895 points

Hi Sir,

customer question as below:

if input is 3.3v , why A1=1.3V, B1 will be pull high to 1.8v , VIH=VCCI * 0.65= 3.3V * 0.65= 2.145V?

0 Rami Mooti1 over 4 years ago in reply to Tommy Tzeng

TI__Mastermind 35648 points

Hey Tommy,

The FAQ Dylan linked should be helpful
[FAQ] Why does my device not switch at VIH or VIL?

They're applying a voltage around ½V_cc, which is causing the device to switch, as it typically should since the threshold voltage is about ½V_cc. Note that the threshold voltage is not the same thing as the V_IHand V_ILvalues.
The input level they're providing isn't recommended, as explained in the final section of the FAQ. Your inputs should meet the V_IH or V_IL recommended operating conditions.

Thanks,
Rami

Logic

Logic forum

TXB0302: VIH and VIL inquire