TPA3132D2: Peak Current Consumption Estimation

[FAE] Andrew Wang

Part Number: TPA3132D2

Hi Team,

If we want to estimate input power current consumption under a given use condition, please help me to check if my calculation looks ok or not, thanks!

PVCC = 24V

Output = 18W

Load = 4 ohms

THD <= 1%

Mode = BTL

Assume Gain = 20 (dB)

Assume efficiency is 90%

Assume we use input divider to limit input voltage to 0.9 Vrms

No additional PLIMIT

Calculation:

Eff is 90%, so PVCC power consume 18W / 0.9 = 20W

Peak power = 20W * 1.414 = 28.28W

PVCC = 24V, IVCC = 28.28W / 24V = 1.178 A (pk) -> this is for output 18W

Assume quiescent supply current = 30mA at PVCC = 24V

Total current consumption is 1.178 A + 30mA = 1.208A (pk)

Is my calculation sounds ok to you?

Thanks.

Andrew

over 4 years ago

0 Sam(MPAA) Zhang over 4 years ago

TI__Mastermind 19080 points

Hi Andrew,

Please find the calculation below,

Eff is 90%, peaker power is 18W(should come from system spec), so PVCC power consume 18W / 0.9 = 20W;

Leave 20% margin for the PVCC power supply, 20/0.8=25W;

PVCC = 24V, IVCC = 25W/24V = 1.041 A (pk) ;

Furthermore, the total current consumption may not be calculated as the quiescent supply current plus the output current...

To get how much power needed from the power supply before the DC/DC which generates the PVCC, it should be calculated out by Pout/efficiency.

Thanks!

Regards,

Sam

0 [FAE] Andrew Wang over 4 years ago in reply to Sam(MPAA) Zhang

TI__Genius 10685 points

Hi Sam,

Thanks for feedback.

Sorry I didn't specify output power is RMS, not PEAK. So you still need to multiply the result by 1.414 I think.

I catch your point of 20% margin is safe way to do, thanks.

Andrew

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TPA3132D2: Peak Current Consumption Estimation