DS25BR440: Interface forum

Kuramochi Tadahiko

Part Number: DS25BR440
Other Parts Discussed in Thread: DS25BR204

Hi,

I heard that "The input and output are not connected when PWDN# = L. No signal will be output from the device" on below thread.

However output signal appears even if PWDN# = L.

Is previous answer correct surely?

Best Regards,

Kuramochi

over 6 years ago

0 Kuramochi Tadahiko over 6 years ago

Guru 28715 points

I attach waveforms.

DS25BR440 waveforms.xlsx

0 Kuramochi Tadahiko over 6 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

Could you please respond anything?

0 Lee Sledjeski over 6 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 43795 points

Hi,

The closest device I have in an EVM is the DS25BR204. This device uses the same base design as the DS25BR440 and DS25CP104.

When I pull PWDN = Low the output is shut off with < 20mV of noise remaining. Do you see this behavior on other channels and other devices?

Regards,

Lee

0 Kuramochi Tadahiko over 6 years ago in reply to Lee Sledjeski

Guru 28715 points

Lee-san,

Thank you for your support.

Could you provide observed waveforms?

Best Regards,

Kuramochi

0 Lee Sledjeski over 6 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 43795 points

Hi Kuramochi,

Here are the Active and PWDN waveforms of the DS25BR204 output. The output is a 100MHz clock pattern.

Regards,

Lee

0 Kuramochi Tadahiko over 6 years ago in reply to Lee Sledjeski

Guru 28715 points

Lee-san,

Thank you for your help.

DC voltage is 0V, right?

I would like to know if VCM(1.2V) is outputted at single end whiled power down mode.

Best Regards,

Kuramochi

0 Lee Sledjeski over 6 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 43795 points

Hi Kuramochi-san,

In this measurement the scope I used requires AC coupling to the LVDS signal. I measured the DC signal content at the device output pins with a voltmeter.

Enabled: Output common mode voltage = 1.23V

Disabled: Output common mode voltage = 1.22V

Regards,

Lee