BUF634A: How to achieve output current of 500mA

Sadanori Kato

Guru 36540 points

Part Number: BUF634A
Other Parts Discussed in Thread: THS3491, OPA1656, OPA1611

Hi,

Is it possible to use two BUF634A in parallel to achieve the output current of 500mA as follows?

Best regards,

Kato

over 5 years ago

0 Michael Steffes over 5 years ago

Guru 48395 points

When you parallel power amps for load sharing you need a ballast resistor to share the current suppress excessive output to output currents due to mismatched offset voltage, this document digs pretty deeply into that, but gives you the basics as well,

paralleling THS3491 for load sharing reference design.pdf

0 Sadanori Kato over 5 years ago in reply to Michael Steffes

Guru 36540 points

Hi Michael-san,

Thank you for the information.

THS3491 is the current feedback amplifier. So, is it possible to apply the topology which is mentioned in this document to voltage feedback amplifier as well?
Are the series resistors(Rs1 and Rs2) which is mentioned in "2.3.1.1 Concept of Load-Sharing Configuration" also necessary for the voltage feed amplifier?
Additionally, should two OPA1656 be added as well if using two BUF634A in parallel?

Best regards,
Kato

0 Hasan Babiker31 over 5 years ago in reply to Sadanori Kato

TI__Genius 15565 points

Hello Kato,

Yes this topology can be applied with voltage-feedback amplifiers, and section 2.3.1.1 is also applicable. You can use BUF634A devices in parallel with only one OPA1656 device. Take a look at the thread below:

Best,

Hasan Babiker

0 Sadanori Kato over 5 years ago in reply to Hasan Babiker31

Guru 36540 points

Hi Hasan-san,

Thank you for your quick response.

I understand.

By the way, could you please give me your comment about the following post?

OPA1611: Isolation Resistor
https://e2e.ti.com/support/audio/f/6/t/928473

Best regards,
Kato

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BUF634A: How to achieve output current of 500mA