Query related Trip zone in 28069

Hi Amtech,

Amtech said:

I also observed when this event occurred at that time ambient temperature is above 55 degree. When temperature is decreased to 40 degree automatic TZ2 signal become 3.3V and PWM are generating. 

This makes no sense! The device operating temperature range is till 100dC +

Leave the TZ pin open and don't connect the resistor. Also, TZCTL is the register that helps you configure the TZ.

Regards,

Gautam

Dear Gautam,

Thank you for your reply.

Yes device working till 100C. but at present i face this type problem and  i try to find out solution. Its related software or hardware.

if any one face than it will help me fast.

Amtech said:

Its related software or hardware.

Seems more like a hardware issue. Did you follow my instructions above? If so, what did you observe?

Regards,

Gautam

Hello,

Amtech said:

I am using F28069 piccolo DSP. I used TZ2(pin no 55,GPIO16 as TZ2 pin configuration) as CBC configuration. I simply pull up this pin with 1k resistor with 3.3Volt supply. I am using PWM7A and PWM8A for gate pulse.

Is this in your custom board or TI kit?

Best regards,

Maria

My custom board.

Dear Gautam,

I put my query again with detail description.

I am using F28069 piccolo DSP. I used TZ2(pin no 55,GPIO16 as TZ2 pin configuration) as CBC configuration. I simply pull up this pin with 1k resistor with 3.3Volt supply. I am using PWM7A and PWM8A for gate pulse.

Now i power up the control card and start the PWM7A and 8A . everything is OK. there is 3.3V on TZ2 pin. but after 15 to 20 mins i measure 0.12V on TZ2 pin, because of this CBC is work and output PWM are disable.

We have 28 control card same DSP and we observed this type problem in 2 control cards.

I can't found why this happen. I simply pull the resistor on TZ2 pin.There is no other hardware on this. than also why this pin become low?

"Leave the TZ pin open and don't connect the resistor. Also, TZCTL is the register that helps you configure the TZ"

I already configured TZ.

Also i faced some time, PWM7A give continuous output high. We have 28 control card same DSP and we observed this type problem in 11 control cards.

Thanks

Amtech said:

I simply pull up this pin with 1k resistor with 3.3Volt supply.

Again I've the same question, why pull-up? No pull-up is required for TZ.

Regards,

Gautam

Dear gautam,

Actually we have open collector comparator (LM211D, TI make) logic on TZ pin so we put pull up resistor.

Amtech said:

Actually we have open collector comparator (LM211D, TI make) logic on TZ pin so we put pull up resistor.

Ok, cool. You can check one thing, monitor the TZ flags in CCS debug window. Also, check your comparator output at the same time. There's a possibility that the comparator or inputs to comparators might be miss-behaving and false triggering TZ.

Regards,

Gautam