Philips TDA8920 Datasheet

INTEGRATED CIRCUITS

DATA SH EET

TDA8920

2 × 50 W class-D power amplifier

Preliminary specification
File under Integrated Circuits, IC01

1998 Dec 01

Philips Semiconductors Preliminary specification

2 × 50 W class-D power amplifier TDA8920

FEATURES

• High efficiency (90%)

• Operating voltage from ±15Vto±30 V

• Very low quiescent current

APPLICATIONS

• Television sets

• Home-sound systems

• Multimedia systems.

• Low distortion

• Fixed gain of 30 dB

• High output power

• Output power limiter

• Good ripple rejection

• Usable as a mono amplifier in Bridge-Tied Load (BTL) or

as a stereo Single-Ended (SE) amplifier

GENERAL DESCRIPTION

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
±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

I

q(tot)

η efficiency P

operating supply voltage ±15 ±25 ±30 V
total quiescent current − 50 60 mA

= 10 W 85 90 − %

o

Stereo single-ended configuration

P

o

G

v(cl)

Z

 input impedance 80 120 − kΩ

i

V

n(o)

output power THD = 10% tbf 35 − W
closed loop voltage gain 29 30 31 dB

noise output voltage − 100 −µV

SVRR supply voltage ripple rejection 60 −−dB

α

cs

channel separation 50 tbf − dB

Mono bridge-tied load configuration

P

o

G

v(cl)

 input impedance 40 60 − kΩ

Z

i

V

n(o)

output power THD = 10% − 130 − W
closed loop voltage gain 35 36 37 dB

noise output voltage − 140 −µV

SVRR supply voltage ripple rejection 66 −−dB

∆V

 DC output offset voltage −−50 mV

O

1998 Dec 01 2

Philips Semiconductors Preliminary specification

2 × 50 W class-D power amplifier TDA8920

ORDERING INFORMATION

TYPE

NUMBER

NAME DESCRIPTION VERSION

PACKAGE

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

handbook, full pagewidth

IN1+

IN1−

LIM

4

3

16

ANALOG

PROTECTION

V

DIGITAL

TDA8920J

DD2

13 5

V

V

DD1

SS1

DD2

6

BOOT1

7

OUT1

12

BOOT2

IN2+

IN2−

MODE

14

ANALOG

15

17

MODE OSCILLATOR STABILIZER

2

SGND

DIGITAL

1

OSC

V

SS1

Fig.1 Block diagram (SOT243-1).

11

V

SS2

9

810

V

SS2

OUT2

STAB

MGR657

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)
IN1− 3 negative input channel 1
IN1+ 4 positive input channel 1
V

DD1

5 positive supply voltage 1
BOOT1 6 bootstrapping capacitor 1
OUT1 7 output 1
V

SS1

8 negative supply voltage 1; note 1
STAB 9 internal stabilizer decoupling
V

SS2

10 negative supply voltage 2; note 1
OUT2 11 output 2
BOOT2 12 bootstrapping capacitor 2
V

DD2

13 positive supply voltage 2
IN2+ 14 positive input channel 2
IN2− 15 negative input channel 2
LIM 16 current limiting adjustment
MODE 17 mode select input

Note

1. The case of the package is connected to pins 8 and 10
(V

SS1

and V

). Therefore no other voltage than V

SS2

should be connected to the case or the heatsink.

SS

handbook, halfpage

OSC

SGND

IN1−
IN1+

V

DD1

BOOT1

OUT1

V

SS1

STAB

V

SS2

OUT2

BOOT2

V

DD2

IN2+
IN2−

LIM

MODE

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17

TDA8920J

MGR658

1998 Dec 01 4

Fig.2 Pin configuration (SOT243-1).

Philips Semiconductors Preliminary specification

2 × 50 W class-D power amplifier TDA8920

FUNCTIONAL DESCRIPTION

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:

• Mono bridge-tied load amplifier

• Stereo single-ended amplifiers.

The amplifier can be switched in three operating modes
with the mode select input:

• Standby mode, with a very low supply current
(practically zero)

• Mute mode; the amplifiers are operational but the audio
signal at the output is suppressed

• 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.

Pulse Width Modulation (PWM) frequency

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

connected between pin OSC

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:

Current limiting

With an external resistor R

connected between pin LIM

LIM

and VSS the maximum output current of the amplifiers can
be set. If pin LIM is short-circuited to VSS, then the
maximum output current is limited to 7 A. The relationship
between maximum output current and resistor value is
given by:

3

I

O(max)

70.10

------------------------------------------ -



10.103R



+

A[]=

LIM

Protections

Protections are included to avoid the device being
damaged at:

• Over-temperature T

> 150 °C

j

• 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

. During

LIM

limiting the current is measured and when the current is
higher than 7 A, the amplifier is switched off within 3 µs
and every 20 ms the IC tries to restart. The dissipation
will be low because of this low duty cycle.

• ESD protection (human body model: 3000 V and
machine model: 300 V).

handbook, halfpage

+5 V

9

5.10

f

osc

-------------­R

OSC

Hz[]=

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.

1998 Dec 01 5

R

standby/on

mute

R

MGR660

pin MODE

SGND

Fig.3 Mode select input drive circuit.