TPA2000D1: TPA2000D1

Greg Nelson84

Part Number: TPA2000D1

Hello,

I would like to adjust the gain of this amplifier to produce a louder audio output. Pins 4 and 5 (GAIN0 and GAIN1) can be used to adjust the gain. The datasheet says the gains can be adjusted by changing the taps on the input resistors inside the amplifier by supplying TTL logic level (assuming 2VDC to 5VDC). Do I need to add an external resistor network to the pins, or will supplying a straight 5VDC be acceptable to adjust the gain? Any clarification would be greatly appreciated.

over 8 years ago

0 José Luis over 8 years ago

TI__Mastermind 20085 points

Hi Greg,

The datasheet means input impedance inside of the amplifier. You don't need to add any external resistor, it is just necessary to set TTL logic lever to Gain0 and Gain1 pins to change the gain of the amplifier.

Best Regards
José Luis Figueroa
Audio Applications Engineer

0 Greg Nelson84 over 8 years ago in reply to José Luis

Prodigy 75 points

Jose,

Thank you for the response. That's what I was assuming but wanted to make sure. I'm measuring a gain of 3dB with this amplifier. GAIN0 and GAIN1 are open i.e. there is no input to these pins. According to the datasheet, I should be seeing a gain of 6dB with a logic level of 0 0. Do I need to physically tie these to ground to get the 6dB of gain?

Thank you,
Greg

0 José Luis over 8 years ago in reply to Greg Nelson84

TI__Mastermind 20085 points

Greg,

Yes, you do. It is necessary to tie these pins to ground in order to get the 6 dB of gain.

Best Regards
José Luis Figueroa
Audio Applications Engineer

0 Greg Nelson84 over 8 years ago in reply to José Luis

Prodigy 75 points

Thanks, Jose. Tying the GAIN0 and GAIN1 pins low (to ground) produced no noticeable difference from when the pins are open. A voltage gain of 3dB is still being measure at the amplifier's input/output. The chip has been wired per the datasheet. Any idea as to why we're not seeing a difference?

Thanks,
Greg

0 José Luis over 8 years ago in reply to Greg Nelson84

TI__Mastermind 20085 points

Hi Greg,

Could you provide me a schematic to review it?

Best Regards
José Luis Figueroa
Audio Applications Engineer

0 Greg Nelson84 over 8 years ago in reply to José Luis

Prodigy 75 points

Jose,

Absolutely. Is there an email I can send it to you directly?

Thanks,
Greg

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TPA2000D1: TPA2000D1