LM1815: LM1815: Clarification

Murugesan Arumugam

Part Number: LM1815

We are using LM1815 in our design for Tachometer sensing. We need clarification on operating voltage because both “normal operating voltage range” and “absolute Maximum of supply voltage” is mentioned as 12V. Generally, it should not be the case. The absolute Maximum rating should be greater than the normal operating voltage with some margin. Please provide us clarification.

over 2 years ago

0 Josh Wyatt over 2 years ago

TI__Guru* 91206 points

Dear Murugesan -

This datasheet is older format (which does not have separate "recommended operating conditions table" that you see in newer format. This datasheet format shows MAX as 12V in both the ABS MAX section and the EC table. The typical or recommended voltage is 10VDC, as listed in the EC table.

0 Murugesan Arumugam over 2 years ago in reply to Josh Wyatt

Prodigy 20 points

Hi Josh Wyatt,

Just now I saw in below link,

https://www.ti.com/product/LM1815?keyMatch=LM1815

on online under product parameter, it shows Vs (min) = 2V and Vs (max)= 12V.

If possible can you share the new data sheet format. if 10V is typical or recommended voltage, then what is min and max operating condition supply voltage?

Shall I operates with 5V supply?

Regards,

Murugesan A

0 Josh Wyatt over 2 years ago in reply to Murugesan Arumugam

TI__Guru* 91206 points

Dear Murugesan -

5VDC is within the range specified. That would be perfectly fine input voltage to use.

0 Murugesan Arumugam over 2 years ago in reply to Josh Wyatt

Prodigy 20 points

Hi Josh Wyatt,

Thanks for quick response.

Then 12V also is within specified range of operation. We also also use 12V right. In this case, I hope device will not operated under stress?

The ABS rating should be greater than the normal operating voltage with some margin right? Do you have what is the ABS rating of supply voltage?

0 Josh Wyatt over 2 years ago in reply to Murugesan Arumugam

TI__Guru* 91206 points

Dear Murugesan -

The input voltage (VIN and signal) and current limit for this device are related in usage and change based on connections you decide to make.

If you have a look at the Typical Performance Characteristics graphs, you will see the typical is 10V, but max of 12V is graphed and tolerated.

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LM1815: LM1815: Clarification