WHY IMX23 GETS HEATED???

[jyothiveeramall]

Hai,

We are developing a product based on IMX23-MCIMX233DJM4C

which we are powering through 5V/Battery(3.7V-4.1V),booting using SPI NOR

and we are using a converter IC for generation of 15V out and give it for LCD,

when I am trying to boot the board intially the imx23 is fine but after few seconds it is getting started heating,

So I guessed like because of load it may getting heated so I had knocked off LCD ,Boost converter and started booting but still the issue is same,

Can anyone please suggest why IMX23 is getting Heated

And suggest solutions which are available inoder to avoid it,

Regards

Jyothi

[igorpadykov]

Hi jyothi

usually heating is caused by internal LDOs, so

for power recommended to use only battery, it is

LI-ION Battery connection on Figure 10

AN4199 Using the i.MX28 Power Management Unit and Battery Charger

Best regards

igor

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[jyothiveeramall]

Hai Igor,

Thanks for the reply,

What you are saying is to use only Battery fo rpowering the device??

Kindly confirm

If it is so I had following queries for you

1.I had already tested the board with battery but it is same status IC is heating,

2.can you please let me know how IMX23 EVK is working with USB without heating

Can you please suggest,

Regards

Jyothi

[igorpadykov]

Hi jyothi

you can have too many loads on processor, try

to solder board with minimal components: only processsor and DDR

and test. Also one can try i.MX23 EVK for test.

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=IMX23EVK&fpsp=1&tab=Design_Tools_Tab

Best regards

igor

[jyothiveeramall]

Hai Igor,

Thanks for the reply,

I had already done testing by knocking off the power to remaining peripherals except ram,Flash and Processor, but not completely desoldered.

But it is in the same stage IC gets heated.

Kindly suggest,

Regards

Jyothi

[igorpadykov]

Hi jyothi

probably there are short circuits in layout.

Try X screening.

Best regards

igor

[jyothiveeramall]

Hai Igor,

Thanks for the reply,

I will try this but i just want to know the below

If there are any short circuits in the Layout I guess the board may not boot?

But our board is booting and all the peripherals are also working fine.

Can you please confirm whether my guess is right or not?,

Regards

Jyothi

[igorpadykov]

Hi jyothi

board may boot with some short circuits in the layout.

Best regards

igor

[jyothiveeramall]

Hai Igor,

Thanks for the reply,

Will verify what you have mentioned in the earlier reply and will get back to you for further queries,

Regards

Jyothi

[jyothiveeramall]

Hai Igor,

Can you please confirm whether there is any choice of controlling of voltage or power consumption using software

Regards

Jyothi

[igorpadykov]

Hi jyothi

one can slow processor and gate clocks of unused modules,

Figure 4-1. Logical Diagram of Clock Domains

Table 2-12. Recommended Operating States

IMX23RM i.MX23 Applications Processor Reference Manual

Best regards

igor

[jyothiveeramall]

hai Igor ,

Thanks for the reply

Can you please confirm the following

1.As mentioned in EVK schematics(at power section) few capacitors are recommended to use as Low ESR ceramic or Tantulum ?

Why and how the board will effect if we use high ESR value capacitors(Either Tantulum or ceramic)

2.In EVK at power section schematics C66,C8,C50,C1  are used as 33uF ceramaic cpacitor but we are using the same capacitor in custom board as 22uF Ceramaic does this value also affect the functionality else only ESR affects??

3.In EVK C130(in Imx23 power page at USB) is used with value 1uF

but in our custom board we have used it with 4.7uF value will it affect??Kindly confirm

4.In the schematic page it is mentioned to follow the guide line for PCB as

  4.a.VAG Capacitor ground must route to star ground at VSSA2?What it mean Exactly and what happens if we don't route it as mentioned?

  4.b.C150,C70,C31 should be placed very close to DC-DC battery pin-Why and how will it affect the functionality of IC if not placed as mentioned?

Can you please confirm all the above mentioned,

Best Regards

Jyothi

[igorpadykov]

Hi Jyothi

I think you can create

new Community thread for these questions.

Thanks!

Best regards

igor