topic Re: MC34708, Silicon Errata in i.MX Processors

MC34708, Silicon Errata

T_I — Mon, 25 Jun 2012 07:36:22 GMT

We design our custom board based on MCIMX53-START-R.

DDR_Vref is generated in MC34708, But MC34708 have Silicon Errata.

The contents of Silicon Errata as follows.(MC34708ER Rev. 5.0, 4/2012)

"Description:VREFDDR output should be 2% accurate over temp. At 85°C, the output accuracy of

VREFDDR can go as high as 6.5%."

"Workaround:Use an external resistor divider to generate VREFDDR"

Would Freescale make a MCIMX53-START-R before this was informed of it?

Should I use an external resistor divider? Or May I use a MC34708 ?

Re: MC34708, Silicon Errata

NitinSonar — Mon, 25 Jun 2012 08:58:15 GMT

Hi,

Better to use divider circuit. Similar divider is used in iMX53 SABER design as well. Doing so will have flexibility to adjust VREFDDR and hence provide better stability. We have followed similar method for our custom board and works well.

Best Regards

Nitin Sonar

Re: MC34708, Silicon Errata

T_I — Mon, 25 Jun 2012 09:13:25 GMT

Hello,

Thank you for your quick reply. I design it as you taught it.

Thanks,