LME49724: Output voltage under standby mode

JimmyLee

Part Number: LME49724

Hello all,

I use LME49724 for driving my audio ADC.It works very well under active mode.When I disable it by driving ENABLE pin to -18V, its output increases to about 34V while its input is 0v，so is that a normal status?

VDD is +18V，VEE is -18V,Vcom is 2.5V.

over 4 years ago

0 Luis Fernando Rodriguez S. over 4 years ago

TI__Guru* 84915 points

Hi, Jimmy,

This is a curious behavior. I would expect to see both outputs at the same level.

Have you tested different units? Do all the units have the same behavior? Do you have the same results if you reduce the supplies voltage?

Could you share your circuit schematic, please? This could give us a better approach to this issue.

Best regards,
Luis Fernando Rodríguez S.

0 Luis Fernando Rodriguez S. over 4 years ago in reply to Luis Fernando Rodriguez S.

TI__Guru* 84915 points

Hi, Jimmy,

I'm closing this e2e thread due to the inactivity. However, feel free to post any question or observation about this case. We will be glad to help you.

Best regards,
Luis Fernando Rodríguez S.

0 Lenny Novikov over 4 years ago in reply to Luis Fernando Rodriguez S.

Prodigy 30 points

Hi Luis,

I have the same problem. I have built a circuit of Figure 51 of the datasheet (Single-ended to balanced converter) with all resistors of 1Kohm, and tested the EN pin performance. When the EN pin is connected to Vss (-15V), the outputs get stuck to the opposite power rails exactly as shown on Jimmy's picture.

I have tested two units recently purchased from Mouser. I believe these are the original parts.

Any suggestions?

Best regards,

Lenny Novikov

0 Luis Fernando Rodriguez S. over 4 years ago in reply to Lenny Novikov

TI__Guru* 84915 points

Hi, Lenny,

Thank you for providing the details about this issue.

Could you provide more details about your circuit? Do you have details about the connected load? Do you have the same results if you use a different load or no load? Do you have details about the power supplies before and after you place the EN pin at VSS (-15V)?

Best regards,
Luis Fernando Rodríguez S.

Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

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LME49724: Output voltage under standby mode