LMH0303: How can the part be wired to run without SMBus management?

Ken Landaiche

Part Number: LMH0303

I'm adding an HD-SDI output to a board with no SMBus controller. Apparently, from this answer, http://e2e.ti.com/support/interface/high_speed_interface/f/138/p/410558/1458741#1458741, I can leave the SCL/SDA pins open in "pin mode". But the data sheet I have has no mention of a "pin mode". Is that just not connecting those two SMBus pins?

SD/HD is pulled down; RSTI is pulled up. RREF has 750 ohms to VCC. Is that all I need to run this part in pin mode?

Many thanks, Ken

over 8 years ago

0 Michael Lu (Santa Clara) over 8 years ago

TI__Mastermind 29655 points

Hi Ken,

Pin mode is simply using the strap pin settings to set up the LMH0303. Even though the SMBus pins are not being used, I would still recommend that you apply external pull-ups since these pins are open-drain. This will prevent the pins from toggling unintentionally.

Regarding your other settings, I would also add a pull-up to the FAULT pin. All your other settings look reasonable to me.

Michael

0 Ken Landaiche over 8 years ago in reply to Michael Lu (Santa Clara)

Prodigy 40 points

Many thanks, Michael.

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LMH0303: How can the part be wired to run without SMBus management?