Functional Description - Philips TDA8542 Datasheet

Philips Semiconductors
2 1 W BTL audio amplifier
PINNING
SYMBOL PIN
LGND 1
OUTL+ 2
MODE 3
SVR 4
BTL/SE 5
n.c. 6
OUTR+ 7
RGND 8
V 9
CCR
OUTR 10
INR 11
INR+ 12
INL+ 13
INL 14
OUTL 15
V 16
CCL
handbook, halfpage
LGND 1
2
OUTL
3
MODE
4
SVR
BTL/SE 5
n.c. 6
OUTR 7
8
RGND
Fig.2 Pin configuration.
1998 Apr 01
DESCRIPTION
ground, left channel
positive loudspeaker terminal,
left channel
operating mode select (standby,
mute, operating)
half supply voltage, decoupling
ripple rejection
BTL loudspeaker or SE
headphone operation
not connected
positive loudspeaker terminal,
right channel
ground, right channel
supply voltage, right channel
negative loudspeaker terminal,
right channel
negative input, right channel
positive input, right channel
positive input, left channel
negative input, left channel
negative loudspeaker terminal,
left channel
supply voltage, left channel
16
V CCL
15
OUTL
14
INL
13
INL
TDA8542
12
INR
11 INR
10 OUTR
9
V CCR
MGB974

FUNCTIONAL DESCRIPTION

The TDA8542(T) is a 2
capable of delivering 2
at THD = 10% using a 5 V power supply. Using the MODE
pin the device can be switched to standby and mute
condition. The device is protected by an internal thermal
shutdown protection mechanism. The gain can be set
within a range from 6 dB to 30 dB by external feedback
resistors.
Power amplifier
The power amplifier is a Bridge Tied Load (BTL) amplifier
with a complementary PNP-NPN output stage.
The voltage loss on the positive supply line is the
saturation voltage of a PNP power transistor, on the
negative side the saturation voltage of a NPN power
transistor. The total voltage loss is <1 V and with a 5 V
supply voltage and an 8
1 W can be delivered.
Mode select pin
The device is in the standby mode (with a very low current
consumption) if the voltage at the MODE pin is
>(V 0.5 V), or if this pin is floating. At a MODE voltage
CC
level of less than 0.5 V the amplifier is fully operational.
In the range between 1.5 V and V
is in mute condition. The mute condition is useful to
suppress plop noise at the output caused by charging of
the input capacitor.
Headphone connection
A headphone can be connected to the amplifier using two
coupling capacitors for each channel. The common
GND pin of the headphone is connected to the ground of
the amplifier (see Fig.13). In this case the BTL/SE pin must
be either on a logic HIGH level or not connected at all.
The two coupling capacitors can be omitted if it is allowed
to connect the common GND pin of the headphone jack
not to ground, but to a voltage level of
In this case the BTL/SE pin must be either on a logic LOW
level or connected to ground. If the BTL/SE pin is on a
LOW level, the power amplifier for the positive
loudspeaker terminal is always in mute condition.
4
Product specification
TDA8542
1 W BTL audio power amplifier
1 W output power to an 8
loudspeaker an output power of
1.5 V the amplifier
CC
1
V (see Fig.13).
2 CC
load