RC4580: power sequencing

Genius 16495 points

Part Number: RC4580

Hi all

My customer is using the

RC4580 Dual, 32-V, 12-MHz, low noise (6.5-nV/√Hz) operational amplifier RC4580IDR

And they have this question:

The supply is +/-15V, where the -15V is delayed for power on and off vs. the +15V.

Is that ok ?

Best regards

Ueli

9 months ago

+1 Ron Michallick 9 months ago

TI__Guru*** 145766 points

Hello Ueli,

That is acceptable. However make sure that no inputs are connected directly (no series resistor) to ground.

0 Ue 9 months ago in reply to Ron Michallick

TI__Genius 16495 points

Hello Ron

Thank you for the quick reply !

Best regards

Ueli

0 Ue 9 months ago in reply to Ue

TI__Genius 16495 points

Hello Ron

Below comes the feedback from the customer. Is this a problem ?

And if yes: How can this be addressed ?

Best regards

Ueli

-----------------------------------

Hello Ueli,

Thanks for your support.

Below reply is noticed.

“However make sure that no inputs are connected directly (no series resistor) to ground.”

Actually, one input is connected to ground (Details see below circuit).

0 Ron Michallick 9 months ago in reply to Ue

TI__Guru*** 145766 points

Uei,

During times when +15V is powered and -15V is not, the -15V bus may become slightly positive. If greater than +300mV, then pin 3 current will flow. If current is excessive then pin 3 may be damaged. If pin 3 damage is significant enough, then channel B may also be affected.

0 Ue 9 months ago in reply to Ron Michallick

TI__Genius 16495 points

Ron

Thank you for the quick reply.

Could one just insert a series resistor from +input to GND to limit the current to a safe value ?

Best regards

Ueli

0 Ron Michallick 9 months ago in reply to Ue

TI__Guru*** 145766 points

Ueli,

Yes, 1k is safe.

0 Ue 9 months ago in reply to Ron Michallick

TI__Genius 16495 points

Hi Ron

Very good, thank you for the confirmation.

Best regards

Ueli

Audio

Audio forum

RC4580: power sequencing