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PSoC 4 MCU

Anonymous
Not applicable

Hi. I have a few cy8c4124pvi-432. If the Vdd (=Vccd) voltage exceeds 4.5 V they burn! What am I doing wrong? Please help!

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6 Replies
RaAl_264636
Contributor II

Hi psix,

   

 

   

without knowing your circuit it's hard to give help. Please post your circuit.

   

 

   

Regards,

   

 

   

Ralf

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Anonymous
Not applicable

2 wires from power supply. 1st to Vdd and Vccd, 2nd to Vss. 4.55V = 3.6A and burn. (at 3.3V = 0A, chip works ok)

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ETRO_SSN583
Esteemed Contributor

The part is rated at 6V absolute max. From the datasheet -

   

 

   

Unregulated External Supply
In this mode, the PSoC 4100 is powered by an External Power
Supply that can be anywhere in the range of 1.8 to 5.5 V. This
range is also designed for battery-powered operation, for
instance, the chip can be powered from a battery system that
starts at 3.5 V and works down to 1.8 V. In this mode, the internal
regulator of the PSoC 4100 supplies the internal logic and the
VCCD output of the PSoC 4100 must be bypassed to ground via
an external Capacitor (in the range of 1 to 1.6 µF; X5R ceramic
or better).

   


VDDA and VDDD must be shorted together; the grounds, VSSA
and VSS must also be shorted together. Bypass capacitors must
be used from VDDD to ground, typical practice for systems in this
frequency range is to use a capacitor in the 1 µF range in parallel
with a smaller capacitor (0.1 µF for example). Note that these are
simply rules of thumb and that, for critical applications, the PCB
layout, lead inductance, and the Bypass capacitor parasitic
should be simulated to design and obtain optimal bypassing.
An example of a bypass scheme for the 44-TQFP package
follows.

   

 

   

I think your VCCD should have been bypassed, as its an internally

   

regulated supply.

   

 

   

Regards, Dana.

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Anonymous
Not applicable

I feel myself so stupid... Now it works fine. Thanks very much indeed! 

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ETRO_SSN583
Esteemed Contributor

Welcome to my club :), glad to have helped.

   

 

   

Regards, Dana.

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RaAl_264636
Contributor II

Aaaaah, sorry, I didn't think about the two power supply modes. My fault.

   

 

   

Regards,

   

 

   

Ralf

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