TDA8920J, ,
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INTEGRATED CIRCUITS
DATA SHEET
TDA8920
2
50 W class-D power amplifier
´
1998 Dec 01
Preliminary specification
File under Integrated Circuits, IC01
Philips Semiconductors
Preliminary specification
2
´
50 W class-D power amplifier
TDA8920
FEATURES
APPLICATIONS
·
High efficiency (90%)
·
Television sets
·
Operating voltage from
±
15Vto
±
30 V
·
Home-sound systems
Very low quiescent current
Multimedia systems.
·
·
·
Low distortion
GENERAL DESCRIPTION
·
Fixed gain of 30 dB
High output power
·
The TDA8920 is a high efficiency class-D audio power
amplifier. It can be used in a mono Bridge-Tied Load (BTL)
or in a stereo Single-Ended (SE) configuration. The device
operates over a wide supply voltage range from
±
·
Output power limiter
·
Good ripple rejection
Usable as a mono amplifier in Bridge-Tied Load (BTL) or
as a stereo Single-Ended (SE) amplifier
·
15Vupto
±
30 V and consumes a very low quiescent
current.
·
Tracking possibility for oscillator frequency
·
Differential audio inputs
·
No switch-on or switch-off plops
·
Short-circuit proof across the load
·
Electrostatic discharge protection on all pins
·
Thermally protected.
QUICK REFERENCE DATA
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
General
V
DD
operating supply voltage
±
15
±
25
±
30
V
I
q(tot)
total quiescent current
-
50
60
mA
h
efficiency
P
o
= 10 W
85
90
-
%
Stereo single-ended configuration
P
o
output power
THD = 10%
tbf
35
-
W
G
v(cl)
closed loop voltage gain
29
30
31
dB
ï
Z
i
ï
input impedance
80
120
-
k
W
V
n(o)
noise output voltage
-
100
-
m
V
SVRR
supply voltage ripple rejection
60
-
-
dB
a
cs
channel separation
50
tbf
-
dB
Mono bridge-tied load configuration
P
o
output power
THD = 10%
-
130
-
W
G
v(cl)
closed loop voltage gain
35
36
37
dB
ï
Z
i
ï
input impedance
40
60
-
k
W
V
n(o)
noise output voltage
-
140
-
m
V
SVRR
supply voltage ripple rejection
66
-
-
dB
ïD
V
O
ï
DC output offset voltage
-
-
50
mV
1998 Dec 01
2
Philips Semiconductors
Preliminary specification
2
´
50 W class-D power amplifier
TDA8920
ORDERING INFORMATION
PACKAGE
TYPE
NUMBER
NAME
DESCRIPTION
VERSION
TDA8920J
DBS17P
plastic DIL-bent-SIL power package; 17 leads (lead length 12 mm)
SOT243-1
TDA8920TH
HSOP20
heatsink small outline package; 20 leads
SOT418-1
BLOCK DIAGRAM
V
DD2
V
DD1
handbook, full pagewidth
13
5
6
BOOT1
4
IN1
+
7
ANALOG
OUT1
DIGITAL
3
IN1
-
V
SS1
16
TDA8920J
LIM
PROTECTION
12
BOOT2
V
DD2
14
IN2
+
11
OUT2
ANALOG
DIGITAL
15
IN2
-
V
SS2
17
9
MODE
MODE
OSCILLATOR
STABILIZER
STAB
2
1
8
10
V
SS1
V
SS2
SGND
OSC
MGR657
Fig.1 Block diagram (SOT243-1).
1998 Dec 01
3
Philips Semiconductors
Preliminary specification
2
´
50 W class-D power amplifier
TDA8920
PINNING
SYMBOL
PIN
DESCRIPTION
OSC
1
oscillator frequency adjustment
SGND
2
signal ground (0 V)
handbook, halfpage
IN1
-
3
negative input channel 1
OSC
1
IN1+
4
positive input channel 1
SGND
2
V
DD1
5
positive supply voltage 1
IN1
-
3
BOOT1
6
bootstrapping capacitor 1
IN1
+
4
OUT1
7
output 1
V
DD1
5
V
SS1
8
negative supply voltage 1; note 1
BOOT1
6
STAB
9
internal stabilizer decoupling
V
SS2
10
negative supply voltage 2; note 1
OUT1
7
OUT2
11
output 2
V
SS1
8
BOOT2
12
bootstrapping capacitor 2
9
TDA8920J
STAB
V
DD2
13
positive supply voltage 2
10
V
SS2
IN2+
14
positive input channel 2
11
OUT2
IN2
-
15
negative input channel 2
BOOT2
12
LIM
16
current limiting adjustment
V
DD2
IN2
13
MODE
17
mode select input
+
14
Note
1.
IN2
-
15
The case of the package is connected to pins 8 and 10
(V
SS1
and V
SS2
). Therefore no other voltage than V
SS
should be connected to the case or the heatsink.
LIM
16
MODE
17
MGR658
Fig.2 Pin configuration (SOT243-1).
1998 Dec 01
4
Philips Semiconductors
Preliminary specification
2
´
50 W class-D power amplifier
TDA8920
FUNCTIONAL DESCRIPTION
Current limiting
The TDA8920 is a multi purpose audio power amplifier in
class-D technology. It contains two independent amplifiers
with high output power, high efficiency (90%), low
distortion and a low quiescent current. The amplifiers can
be connected in the following configurations:
·
With an external resistor R
LIM
connected between pin LIM
and V
SS
the maximum output current of the amplifiers can
be set. If pin LIM is short-circuited to V
SS
, then the
maximum output current is limited to 7 A. The relationship
between maximum output current and resistor value is
given by:
Mono bridge-tied load amplifier
·
Stereo single-ended amplifiers.
The amplifier can be switched in three operating modes
with the mode select input:
·
70.10
3
10.10
3
I
O(max)
=
-------------------------------------------
[]
æ
ö
+
R
LIM
è
ø
Standby mode, with a very low supply current
(practically zero)
Protections
Protections are included to avoid the device being
damaged at:
·
·
Mute mode; the amplifiers are operational but the audio
signal at the output is suppressed
Over-temperature T
j
> 150
°
C
·
Operating mode (amplifier fully operational) with output
signal.
For suppressing plop noise the amplifier will remain
automatically for approximately 500 ms in the mute
mode before switching to operating mode. During this
time the coupling capacitors at the input are fully
charged. An example of a switching circuit for driving the
mode select input is illustrated in Fig.3.
·
Short-circuit of the loudspeaker terminals: when
short-circuited the power dissipation is limited
·
A maximum current limiter which limits the maximum
output current to 7 A, or to the value set by R
LIM
. During
limiting the current is measured and when the current is
higher than 7 A, the amplifier is switched off within 3
s
and every 20 ms the IC tries to restart. The dissipation
will be low because of this low duty cycle.
m
Pulse Width Modulation (PWM) frequency
·
ESD protection (human body model: 3000 V and
machine model: 300 V).
The output signal of the amplifier is a PWM signal with a
sample frequency of 500 kHz. The use of a second order
LC filter in the application results in an analog audio signal
across the loudspeaker. This switching frequency is fixed
by an external resistor R
OSC
connected between pin OSC
and pin SGND. With the resistor value given in the
application diagram, the oscillating frequency is typical
500 kHz. The oscillator frequency can be calculated using:
+
5 V
handbook, halfpage
5.10
9
R
OSC
f
osc
=
--------------
[
Hz
]
R
If two or more devices are used in the same audio system
it is advised to have both devices working on the same
oscillation frequency. This can be realized by connecting
all OSC pins together.
standby/on
pin MODE
R
mute
SGND
MGR660
Fig.3 Mode select input drive circuit.
1998 Dec 01
5
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