Can the Sabre Lite operate at maximum frequency?

[kbell_hardware]

Hello,

I noticed that the Sabre Lite board supplies 1.2V to it's VDDARM input. The IMX6Q datasheet says that the processor needs a minimum of 1.35V to run at 1GHz in LDO mode and 1.225V minimum to run in LDO bypass mode. It appears that the Sabre Lite wouldn't support the 1GHZ ARM Clock frequency, is this true?

1. Does Sabre Lite support operation at 1GHz?

2. Does the Sabre Lite run in LDO Bypassed mode?

I assume the answer to this question would also apply to the maximum SOC frequency

Thanks,

KBell

[EricNelson]

Sorry. I meant to add that SABRE-Lite boards don't operate in LDO_BYPASS mode since they don't have an external PMIC.

[kbell_hardware]

So it would appear that the board can still operate at 1GHz even when the voltage is below spec and it doesn't even need to be in LDO Bypass mode? What are the drawbacks to designing like this?

What does having an external PMIC have to do with being able to operate in LDO Bypass mode? Is there some requirement for that? Don't you just need a low ripple source?

P.S. - My goal is to be able to run LPDDR2 SDRAM off of the same voltage source as the ARM/SOC Cores reducing the number of regulators required. Understanding that i should filter the inputs with ferrites or inductors.

[EricNelson]

Hi Kevin,

You should design to the spec of 1.35V. The fact that things work on 1.0 silicon at lower voltage shouldn't be counted on.

When SABRE Lite was designed, the specs were in flux.

The external PMIC allows the voltages to be lowered during CPU frequency changes.

I'll defer to the Freescalers on ways to reduce the number of regulators and integration of LPDDR.

[EricNelson]

Hi Kevin,

The SABRE Lite can operate at 1GHz, though it is possible to over-drive it with a set of processes stressing each core, plus GPU and VPU.

You can replace a couple of components to bring these rails up to the current spec.