TFA9812HN PHILIPS [NXP Semiconductors], TFA9812HN Datasheet - Page 50

• Manufacturer Part Number: TFA9812HN
• Description: BTL stereo Class-D audio amplifier with I2S input
• Manufacturer: PHILIPS [NXP Semiconductors]

NXP Semiconductors
TFA9812_2
Preliminary data sheet
Fig 11. BTL P
(W/channel)
P
O
(1) 6
(2) 8
(3) 16
(0.5 %)
30
20
10
0
8
14.2 Output current limiting
O
(0.5 %) as a function of V
12
The output power at 10 % THD can be estimated using
Figure 11
THD = 10 % as a function of BTL supply voltage for different load impedances.
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
Where:
V
R
R
R
P
I
max
O max
P
O
L
DSon
S
= load impedance ( )
= supply voltage (V) (V
= series resistance output inductor ( )
(10%)
16
= Maximum duty factor (0.96).
= 'On' resistance power switch ( )
---------------------------------------------------- -
R
12:
=
and
L
1.25 P
+
20
2
Figure 12
(1)
(2)
(3)
010aaa347
V
P
V
R
P
(V)
O
P
DSon
(0.5%)
Rev. 02 — 22 January 2009
24
+
show the estimated output power at THD = 0.5 % and
DDP
R
S
-V
SSP
Fig 12. BTL P
)
W/channel
P
BTL stereo Class-D audio amplifier with I
O
(10 %)
(1) 6
(2) 8
(3) 16
45
30
15
0
8
O
(10 %) as a function of V
12
Equation
16
11:
20
© NXP B.V. 2009. All rights reserved.
TFA9812
(1)
(2)
(3)
010aaa348
V
P
P
(V)
24
2
S input
50 of 66
(11)
(12)