TPA3106D1: Do Differential Inputs Double the Audio Dynamic Range?

johny radio

Part Number: TPA3106D1

Support Path: /Product/Development and troubleshooting/

This article explains that:

"given the same voltage range for single-ended and fully-differential inputs, the fully-differential inputs will have double the dynamic range (Figure 2)."

over 8 years ago

0 Shawn Zheng over 8 years ago

TI__Mastermind 24835 points

Hi Johny,
This article is about ADC, and generally differential input mode doubles the input range, comparing to the single-ended mode with the same power voltage supply for ADC application. But for TPA3106D2 device, the input range is basically not limited by the power supply. Because the maximum input voltage is around 4.5V(VREG+0.5V), so the output is 45V even with minimal gain setting (20 dB), and clipping occurs. It means that the input range generally can't be the bottleneck of the TPA3106D2 application. But please use differential input mode as much as possible, because as you know the common mode noise is canceled in this way.
Best regards,
Shawn Zheng

0 johny radio over 8 years ago in reply to Shawn Zheng

Intellectual 930 points

hi Shawn

Thx for reply.

You mentioned the D2, but I'm asking about the D1 chip.

cheers!

0 Shawn Zheng over 8 years ago in reply to johny radio

TI__Mastermind 24835 points

Hi Johny,
Sorry for the typo. It's D1, not D2. Actually TI only have TPA3106D1.

0 johny radio over 8 years ago in reply to Shawn Zheng

Intellectual 930 points

"the output is 45V even with minimal gain setting (20 dB), and clipping occurs."

i don't understand what you mean. Let's talk about max input V WITHOUT clipping.

In single-ended mode, max INP V = X, and INN V = 0, correct?
In differential mode, max INP V = X, and INN V = -X, correct?

0 Shawn Zheng over 8 years ago in reply to johny radio

TI__Mastermind 24835 points

I mean the single-ended input is enough for the input dynamic range, and you don't need use differential input mode to achieve doubled range.

0 johny radio over 8 years ago in reply to Shawn Zheng

Intellectual 930 points

What do you mean "enough"?

0 Shawn Zheng over 8 years ago in reply to johny radio

TI__Mastermind 24835 points

Your understanding is correct. In most of cases, the input range for single-ended mode is enough. Only for rare cases, Gain setting is small and the output power is very high, then a large input range is needed. So for most of the cases, differential input mode is used to only improve the performance. Please let me know if it's clear.

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TPA3106D1: Do Differential Inputs Double the Audio Dynamic Range?