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
(3)
Where:
•
V
P
= supply voltage (V
DDPx
−
V
SSPx
) [V].
(1) R
L
= 4
Ω
(2) R
L
= 6
Ω
(3) R
L
= 8
Ω
Fig 26. BTL output power as function of supply voltage: THD = 0.5 %. 3 A
(1) R
L
= 4
Ω
(2) R
L
= 6
Ω
(3) R
L
= 8
Ω
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
≤
≤
