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2 output current limiting, Figure 26, Figure 27 – NXP Semiconductors TFA9810 User Manual

Page 19: Belo, Tfa9810, Nxp semiconductors

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TFA9810_3

© NXP B.V. 2008. All rights reserved.

Product data sheet

Rev. 03 — 20 February 2008

19 of 29

NXP Semiconductors

TFA9810

Audio amplifier 2 x 12 W

14.2 Output current limiting

The peak output current is internally limited above a level of 3 A minimum. During normal
operation the output current should not exceed this threshold level of 3 A, otherwise the
output signal will be distorted. The peak output current in BTL can be estimated using

Equation 3

:

(3)

Where:

V

P

= supply voltage (V

DDPx

V

SSPx

) [V].

(1) R

L

= 4

(2) R

L

= 6

(3) R

L

= 8

Fig 26. BTL output power as function of supply voltage: THD = 0.5 %. 3 A

(1) R

L

= 4

(2) R

L

= 6

(3) R

L

= 8

Fig 27. BTL output power as function of supply voltage: THD = 10 %. 3 A

(1)

(2)

(3)

V

P

(V)

8

20

16

12

010aaa019

10

15

5

20

25

P

o

(W)

0

(1)

(2)

(3)

V

P

(V)

8

20

16

12

010aaa020

10

20

30

P

o

(W)

0

I

O

max

V

P

R

L

2

R

DSon

R

s

+

(

)

×

+

------------------------------------------------------

3 A