TDA8943.PDF

(370 KB) Pobierz
6 W mono Bridge Tied Load (BTL) audio amplifier
TDA8943SF
6 W mono Bridge Tied Load (BTL) audio amplifier
Rev. 02 — 7 April 2000
Product specification
1. General description
load and a 12 V supply. The circuit contains a Bridge Tied Load (BTL)
amplifier with an all-NPN output stage and standby/mute logic. The TDA8943SF
comes in a 9-lead single in-line (SIL) medium power package. The TDA8943SF is
printed-circuit board (PCB) compatible with all other types in the TDA894x family.
One PCB footprint accommodates both the mono and the stereo products.
W
2. Features
n
Few external components
n
Fixed gain
n
Standby and mute mode
n
No on/off switching plops
n
Low standby current
n
High supply voltage ripple rejection
n
Outputs short-circuit protected to ground, supply and across the load
n
Thermally protected
c
c
n
Printed-circuit board compatible.
3. Applications
n
Mains fed applications (e.g. TV sound)
n
PC audio
n
Portable audio.
4. Quick reference data
Table 1: Quick reference data
Symbol Parameter
Conditions
Min Typ
Max Unit
V CC
supply voltage
6
12
18
V
I q
quiescent supply current V CC =12V; R L =
¥
-
52A
I stb
standby supply current
-
-
10
m
A
The TDA8943SF is a single-channel audio power amplifier with an output power of
6 W at an 8
11038112.050.png 11038112.053.png 11038112.054.png 11038112.055.png 11038112.001.png 11038112.002.png 11038112.003.png 11038112.004.png 11038112.005.png 11038112.006.png 11038112.007.png 11038112.008.png 11038112.009.png
Philips Semiconductors
TDA8943SF
6 W mono Bridge Tied Load (BTL) audio amplifier
Table 1: Quick reference data …continued
Symbol Parameter
Conditions
Min Typ
Max Unit
P o
output power
THD = 10%; R L =8
W
;
5
6
-
W
V CC =12V
THD
total harmonic distortion P o = 1 W
-
0.03 0.1
%
G v
voltage gain
31
32
33
dB
SVRR supply voltage
ripple rejection
50
65
-
dB
5. Ordering information
Table 2: Ordering information
Type number Package
Name
Description
Version
TDA8943SF
SIL9MPF plastic single in-line medium power package
with fin; 9 leads
SOT110-1
6. Block diagram
idth
V CC
2
TDA8943SF
1
OUT -
5
IN -
IN +
4
3
OUT
+
V CC
MODE
7
STANDBY/
MUTE LOGIC
20
k W
SHORT CIRCUIT
AND
TEMPERATURE
PROTECTION
6
SVR
20
k W
8
MBK942
GND
Fig 1. Block diagram.
9397 750 06865
© Philips Electronics N.V. 2000. All rights reserved.
Product specification
Rev. 02 — 7 April 2000
2 of 20
11038112.010.png 11038112.011.png 11038112.012.png 11038112.013.png 11038112.014.png 11038112.015.png 11038112.016.png 11038112.017.png 11038112.018.png 11038112.019.png 11038112.020.png 11038112.021.png 11038112.022.png 11038112.023.png 11038112.024.png 11038112.025.png 11038112.026.png 11038112.027.png 11038112.028.png 11038112.029.png
Philips Semiconductors
TDA8943SF
6 W mono Bridge Tied Load (BTL) audio amplifier
7. Pinning information
7.1 Pinning
handbook, halfpage
OUT -
1
V CC
OUT
2
+
3
IN +
4
IN -
5
TDA8943SF
SVR
6
MODE
7
GND
8
n.c.
9
MBK941
Fig 2. Pin configuration.
7.2 Pin description
Table 3: Pin description
Symbol
Pin
Description
OUT -
1
negative loudspeaker terminal
V CC
2
supply voltage
OUT+
3
positive loudspeaker terminal
IN+
4
positive input
IN -
5
negative input
SVR
6
half supply voltage decoupling (ripple rejection)
MODE
7
mode selection input (standby, mute, operating)
GND
8
ground
n.c.
9
not connected
8. Functional description
The TDA8943SF is a mono BTL audio power amplifier capable of delivering 6 W
output power to an 8
W
With the three-level MODE input the device can be switched from ‘standby’ to ‘mute’
and to ‘operating’ mode.
The TDA8943SF outputs are protected by an internal thermal shutdown protection
mechanism and a short-circuit protection.
9397 750 06865
© Philips Electronics N.V. 2000. All rights reserved.
Product specification
Rev. 02 — 7 April 2000
3 of 20
load at THD = 10%, using a 12 V power supply and an
external heatsink. The voltage gain is fixed at 32 dB.
11038112.030.png 11038112.031.png 11038112.032.png 11038112.033.png 11038112.034.png 11038112.035.png 11038112.036.png 11038112.037.png 11038112.038.png 11038112.039.png 11038112.040.png 11038112.041.png 11038112.042.png 11038112.043.png 11038112.044.png 11038112.045.png 11038112.046.png 11038112.047.png 11038112.048.png
Philips Semiconductors
TDA8943SF
6 W mono Bridge Tied Load (BTL) audio amplifier
8.1 Input configuration
The TDA8943SF inputs can be driven symmetrical (floating) as well as asymmetrical.
In the asymmetrical mode one input pin is connected via a capacitor to the signal
ground which should be as close as possible to the SVR (electrolytic) capacitor
ground. Note that the DC level of the input pins is half of the supply voltage V CC , so
coupling capacitors for both pins are necessary.
The input cut-off frequency is:
f i cut off
=
-----------------------------
1
(1)
(
–
)
2
p
(
R i
´
C i
)
For R i =45k
W
and C i = 220 nF:
f i cut off
=
----------------------------------------------------------------- 16 Hz
1
=
(2)
(
–
)
45 10 3
–
9
2
p
(
´
´
220
´
10
)
As shown in Equation 1 and 2 , large capacitor values for the inputs are not
necessary ; so the switch-on delay during charging of the input capacitors, can be
minimized. This results in a good low frequency response and good switch-on
behaviour.
Remark: To prevent HF oscillations do not leave the inputs open, connect a capacitor
of at least 1.5 nF across the input pins close to the device.
8.2 Power amplifier
The power amplifier is a Bridge Tied Load (BTL) amplifier with an all-NPN output
stage, capable of delivering a peak output current of 2 A.
The BTL principle offers the following advantages:
• Lower peak value of the supply current
• The ripple frequency on the supply voltage is twice the signal frequency
• No expensive DC-blocking capacitor
• Good low frequency performance.
8.2.1 Output power measurement
The output power as a function of the supply voltage is measured on the output pins
at THD = 10%; see Figure 8 . The maximum output power is limited by the maximum
supply voltage of 12 V and the maximum available output current: 2 A repetitive peak
current.
9397 750 06865
© Philips Electronics N.V. 2000. All rights reserved.
Product specification
Rev. 02 — 7 April 2000
4 of 20
11038112.049.png
 
Philips Semiconductors
TDA8943SF
6 W mono Bridge Tied Load (BTL) audio amplifier
8.2.2 Headroom
and P o = 4 W at THD = 0.1% (see Figure 6 ), the
Average Listening Level (ALL) – music power – without any distortion yields:
P o(ALL) = 4 W/15.85 = 252 mW.
W
The power dissipation can be derived from Figure 11 on page 10 for 0 dB
respectively 12 dB headroom.
Table 4: Power rating as function of headroom
Headroom
Power output (THD = 0.1%)
Power dissipation (P)
0 dB
P o = 4 W
3.8 W
12 dB
P o(ALL) = 252 mW
1.8 W
For the average listening level a power dissipation of 1.8 W can be used for a
heatsink calculation.
8.3 Mode selection
The TDA8943SF has three functional modes, which can be selected by applying the
proper DC voltage to pin MODE. See Figure 4 and 5 for the respective DC levels,
which depend on the supply voltage level. The MODE pin can be driven by a 3-state
logic output stage: e.g. a microcontroller with additional components for DC-level
shifting.
0.5 V) < V MODE <V CC , or when
the MODE pin is left floating (high impedance). The power consumption of the
TDA8943SF will be reduced to <0.18 mW.
Mute — In this mode the amplifier is DC-biased but not operational (no audio output);
t he DC level of the input and output pins remain on half the supply voltage. This
allows the input coupling and Supply Voltage Ripple Rejection (SVRR) capacitors to
be charged to avoid pop-noise. The device is in mute mode when
3V<V MODE <(V CC -
1.5 V).
Operating — In this mode the amplifier is operating normally. The operating mode is
activated at V MODE < 0.5 V.
8.3.1 Switch-on and switch-off
To avoid audible plops during supply voltage switch-on or switch-off, the device is set
to standby mode before the supply voltage is applied (switch-on) or removed
(switch-off).
The switch-on and switch-off time can be influenced by an RC-circuit on the MODE
pin. Rapid on/off switching of the device or the MODE pin may cause ‘click- and
pop-noise’. This can be prevented by proper timing of the RC-circuit on the MODE
pin.
9397 750 06865
© Philips Electronics N.V. 2000. All rights reserved.
Product specification
Rev. 02 — 7 April 2000
5 of 20
Typical CD music requires at least 12 dB (factor 15.85) dynamic headroom –
compared to the average power output – for transferring the loudest parts without
distortion. At V CC =12V, R L =8
Standby — In this mode the current consumption is very low and the outputs are
floating. The device is in standby mode when (V CC -
11038112.051.png 11038112.052.png

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin