SN74GTL2003: SN74GTL2003

Hi Santosh,

Are sure you actually need translation? 300 mV difference is not typically something that requires translation, most of the time there is enough margin between VOH/VOL and VIH/VIL values to accommodate this.

Thanks for the prompt reply Dylan

Yes, I need a level translator just in case things don't work as expected...I want to have a level translator on the PCB, maybe i will not populate (based on the testing) but want to have an option for a level translator

Hey Santosh,

How many channels are needed? What's the target data rate? Are these unidirectional signals or can the data flow in both directions on a single channel?

If I have this info, I can find you the right translator for the job.

Dylan,

I need 8 channels (two 4 channel is also fine)

Datarate is 100Mbps

Bi-directional

Also could you please answer the following queries wrt to PN: SN74GTL2003PW

1) for this part what is the minimum voltage at the lower side(Sn) to get 1.8V at the higher side(Dn)? will this work for 1.5V on Sn and 1.8V on Dn

2) What are the default input and output states of the IOs on both sides on power up and power down conditions?

3) Do I need to connect pull-up resistors on both (Sn and Dn) input and output sides?

4) What should be the value of pull-up resistors on IOs?

Thanks, Dylan

for recommending the TXB0108 device. datasheet of this device says

1) For proper operation, the device driving the data I/Os of the TXB0108 must have a drive strength of at least ±2 mA. Can I place a 1 to4.7Kohm resistor on the A-side?

2) pulldown or pullup resistors are recommended to be larger than 50kΩ....  why is it so? can I use a 1kohm pull-up resistor on the B side?

3) The typical output impedance during output transition is 70 Ω at VCCO = 1.2 V to 1.8 V.....what is the output impedance after the transition is over(after one shot is turned off)?

4) what is the 4kohm resistor with one short circuit?

The TXB's output drivers on both sides are always active, but they are very weak to allow other devices to override the voltage.

Anyway, the TXB cannot achieve 100 Mbps at those low voltages.

TXB0108 will this support both PUSH pull and Open Drain outputs?

No; the TXB works only with push/pull outputs.

TXS0108EPW is the part I am choosing for 1.5V(VCCA) to 1.8V(VCCB) level translation 100Mbps datarate

will this work fine? i am not sure about outputs are open-drain or push-pull as my board is an intermediate board with connectors on both sides of the Level translator

It will not work; the TXB supports only 50 Mbps at these voltages (see section 6.7 of the datasheet), and the capacitance of the connectors and cables is likely to be too high (see section 8.3.3).

I selected TXS, not TXB...data rate is fine 50mbps or 100mbps(i will downgrade the speed for testing)

my concern is about  will it work with 1.5V(VCCA) and 1.8V(VCCB) irrespective of open drain or pushpull