XOR Connection between TAS5604 and TAS5601 in BTL mode

Masaoki Koide

Intellectual 580 points

Other Parts Discussed in Thread: TAS5704, TAS5601, TAS5086

Hi,

Currently our customer uses TAS5704 with TAS5601 as D-AMP for subwoofer.

According to the TAS5704 datasheet page 2, connection between TAS5704 and TAS5601 in BTL mode is as follows.

TAS5601 PWM_AP input is from TAS5704 SUB_PWM+ directly and PWM_AN input is from inverting SUB_PWM+.

PWM_BP/BN and SUB_PWM- is also the same.

On the other hand, According to the application note "Converting Single Line PWM Input Signals to Dual Line Input Signals" (SLOA131) page 2,

the document recommends to use XOR connection instead of the Inverter for PWM negative input such as PWM_AN to make more reliable.

This is in case of using TAS5086 and TAS5261, not same device conbination as above.

Should we use XOR instead of Inverter in the TAS5704 and TAS5601 system?

Or we can use Inverter that shows in the datasheet ?

Please advise.

Regards,

over 7 years ago

0 Diego Melendez over 7 years ago

TI__Guru 57800 points

Hi, Koide,

I think it would be better to use the XOR configuration as both PWM signals will pass over a logic gate, having a same delay at the input of the TAS5601. The block diagram on the TAS5704 datasheet is used as a general operation example, while the XOR diagram is more like an application example

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 Masaoki Koide over 7 years ago in reply to Diego Melendez

Intellectual 580 points

Hi Diego,

Thanks for the advice. I recommend our customer to use XOR cofiguration.

Regards,
Koide

0 Masaoki Koide over 7 years ago in reply to Diego Melendez

Intellectual 580 points

Hi Diego,

May I ask you one more question? Our customer has a following concern.
They understand that they should use XOR to minimize PWM skew creating through the external logic. From a PWM accuracy view point, are there any concerns about creating skew among OUTA/B/C/D by TAS5601 itself and occuring problem?
Thank you for your advice.

Regards,
Koide

0 Masaoki Koide over 7 years ago in reply to Masaoki Koide

Intellectual 580 points

Hi Diego

Could you please give me any comments? Thanks for your advice.

Regards,
Koide

0 Diego Melendez over 7 years ago in reply to Masaoki Koide

TI__Guru 57800 points

Hi, Koide,

I think there should be no issues as long as the path of all the PWM signals into the TAS5604 is the same (i.e, all PWMs going though the same logic gate, processing, etc.). If the differential (+ and -) PWM signals are not in phase or have a delay between each other, audio artifacts might occur in the output of the amplifier.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 Masaoki Koide over 7 years ago in reply to Diego Melendez

Intellectual 580 points

Hi Diego,

Thanks for the kind advice. Understand. I hope that this will make our customer's concerns clear.

Regards,
Koide

Audio

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XOR Connection between TAS5604 and TAS5601 in BTL mode