CD4504B: Voltage Level shifter IC(CD4504B) not working

Tusarkanta Das

Prodigy 80 points

Part Number: CD4504B

Hi,

I have used TI part-CD4504B as per below schematic; but its getting heated up & also damaged.

Connection details -

while testing, only 15V connected. No inputs given & 3.3V also not present.

Is the IC getting failed because of only supply ? Please clarify.

Thanks,

Tusarkanta Das

over 6 years ago

0 Emrys Maier over 6 years ago

TI__Guru* 96977 points

Hello and thanks for your post! Today is a holiday in the US. I just wanted to let you know that we will get back to you on Monday, November 26.

0 Emrys Maier over 6 years ago in reply to Emrys Maier

TI__Guru* 96977 points

Hello,
Not connecting inputs is likely the reason for the failure. You should never leave CMOS inputs floating.

0 Tusarkanta Das over 6 years ago in reply to Emrys Maier

Prodigy 80 points

Hi,

Thanks for your reply.

But normally all the inputs will not be used; out of 6 channel, I need only 2 channel.

So, in that case what shall I do ? Shall I connect pull down resistors to unused channel ?

Thanks,

Tusarkanta Das

0 Emrys Maier over 6 years ago in reply to Tusarkanta Das

TI__Guru* 96977 points

The unused inputs can be directly connected to ground. There is no need for resistors.

0 Tusarkanta Das over 6 years ago in reply to Emrys Maier

Prodigy 80 points

Hi,

Thanks for your suggestion.

Please clarify last point.

- What about 2 used channels; shall I put pull down/pull-up resistors for those ? because that is not continuous signal which is connected to 2 channel.

Thanks,

Tusarkanta Das

0 Emrys Maier over 6 years ago in reply to Tusarkanta Das

TI__Guru* 96977 points

It depends on the state of the channel when it is unused. If it is left floating, a 10kohm pull-up or pull-down resistor can keep it at a valid state.

0 Tusarkanta Das over 6 years ago in reply to Tusarkanta Das

Prodigy 80 points

Thanks for your reply..

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CD4504B: Voltage Level shifter IC(CD4504B) not working