Philips TDA8574T-N1 Datasheet

DATA SH EET

Product specification
Supersedes data of 1997 Feb 26
File under Integrated Circuits, IC01

1998 Oct 16

INTEGRATED CIRCUITS

TDA8574

Class-H high-output voltage level
line driver

1998 Oct 16 2

Philips Semiconductors Product specification

Class-H high-output voltage level line
driver

TDA8574

FEATURES

• Output voltage swing larger than supply voltage

• High supply voltage ripple rejection

• Low distortion

• Low noise

• ESD protected on all pins.

GENERAL DESCRIPTION

The TDA8574(T) is a two channel class-H high-output
voltage line driver for use in car audio applications.
The line driver behaves as a non-inverting amplifier with a
gain of 8 dB and a single-ended output. Due to the class-H
voltage lifting principle the voltage swing over the load is
more than the supply voltage. With a supply voltage of 9 V
the output voltage swing over the load will be
14 V (peak-to-peak).

The TDA8574 is available in a DIP16 package and the
TDA8574T in a SO16 package.

Line drivers are necessary in car audio systems in which
the power amplifiers are driven by long cables.
The signal-to-noise ratio of these car audio systems is
improved by using the TDA8574(T) class-H high-output
level line driver. The high-output level of TDA8574(T)
enables a reduction of the gain of the power amplifier
resulting in an improvement of the power amplifier
performance.

QUICK REFERENCE DATA

ORDERING INFORMATION

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

V

CC

supply voltage 6 9 12 V

I

CC

supply current VCC=9V − 813mA

G

v

voltage gain 7.5 8 8.5 dB

V

o(rms)

maximal output voltage (RMS value) THD = 0.1% 5.0 5.2 − V
SVRR supply voltage ripple rejection 50 65 − dB
THD total harmonic distortion V

o(rms)

= 3 V; f = 1 kHz − 0.003 − %

V

no

noise output voltage − 5 −µV
Z

o

 output impedance −−10 Ω

TYPE

NUMBER

PACKAGE

NAME DESCRIPTION VERSION

TDA8574T SO16 plastic small outline package; 16 leads; body width 7.5 mm SOT162-1
TDA8574 DIP16 plastic dual in-line package; 16 leads (300 mil) SOT38-4

1998 Oct 16 3

Philips Semiconductors Product specification

Class-H high-output voltage level line
driver

TDA8574

BLOCK DIAGRAM

Fig.1 Block diagram.

handbook, full pagewidth

MGE668

24 kΩ

30 kΩ

5 Ω

36 kΩ

36 kΩ

30 kΩ

24 kΩ

REFERENCE

REFERENCE

LIFT

AMP.

LIFT

AMP.

SIGNAL

AMP.

SIGNAL

AMP.

TDA8574(T)

V

CCL

V

CCL

V

CCR

V

CCR

V

CCL

V

CCR

3

1

BUFFER

BUFFER

BUFFER

BUFFER

CL+

CL−

CR+

CR−

OUTL

13

14

11

12

10

9

6

INR

INMR

INML

INL

SVRL

8

15

16

LGND

RGND

OUTR

2
4

5
7

SVRR

+

+

−

+

−

−

+

−

1998 Oct 16 4

Philips Semiconductors Product specification

Class-H high-output voltage level line
driver

TDA8574

PINNING

SYMBOL PIN DESCRIPTION

V

CCL

1 supply voltage left channel
INL 2 input voltage left channel
SVRL 3 SVRR left channel
INML 4 inverting input left channel
INMR 5 inverting input right channel
SVRR 6 SVRR right channel
INR 7 input voltage right channel
V

CCR

8 supply voltage right channel
CR+ 9 lift capacitor (+) right channel
CR− 10 lift capacitor (−) right channel
RGND 11 ground right channel
OUTR 12 output voltage right channel
OUTL 13 output voltage left channel
LGND 14 ground left channel
CL− 15 lift capacitor (−) left channel
CL+ 16 lift capacitor (+) left channel

Fig.2 Pin configuration.

handbook, halfpage

TDA8574

TDA8574T

MGE667

1
2
3
4
5
6
7
8

16
15
14
13
12
11
10

9

V

CCL

INL

SVRL

INML

INMR

SVRR

INR

V

CCR

CR+

CR−

RGND

OUTR

OUTL

LGND

CL−

CL+

FUNCTIONAL DESCRIPTION
Lift amplifier

The lift amplifier, referred to as LIFT AMP. in Fig.1, is used
as a non-inverting amplifier with a voltage gain of 8 dB set
by an internal feedback network. If the output voltage of
the signal amplifier is low, the external lift capacitor is
recharged by the lift amplifier. As soon as the output
voltage of the signal amplifier increases above 0.87 × V

CC

the lift amplifier switches the voltage of the lift capacitor in
series with the supply voltage VCC. The voltage at the
positive side of the lift capacitor is referred to as lifted
supply voltage.

Signal amplifier

The signal amplifier, referred to as SIGNAL AMP. in Fig.1,
is used as a non-inverting amplifier. The voltage gain G

v

is

set by the feedback resistors according to the formula:

and should be set to 8 dB. The LIFT AMP. and SIG AMP.
must have equal voltage gain Gv. The rail-to-rail output
stage of the signal amplifier uses the lifted supply voltage
to increase the output voltage swing.

G

v

1

R

2

R

1

------ -

+=

The DC output level is set to ≈0.87 × V

CC.

The maximum
peak-to-peak output voltage of the signal amplifier is
calculated with the formula:

Buffers

The buffers prevent loading of the internal voltage divider
network made by a series connection of resistors. For a
good supply voltage ripple rejection this internal voltage
divider network has to be decoupled by an external
capacitor.

Reference

This circuit supplies all currents needed in the device.

V

op p–()max

20.87VCC0.4–()×≈

1998 Oct 16 5

Philips Semiconductors Product specification

Class-H high-output voltage level line
driver

TDA8574

LIMITING VALUES

In accordance with the Absolute Maximum Rating System (IEC 134).

THERMAL CHARACTERISTICS

SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT

V

CC

supply voltage operating − 12 V

I

ORM

repetitive peak output current − 20 mA

T

stg

storage temperature −55 +150 °C

T

amb

operating ambient temperature −40 +85 °C

T

j

junction temperature − +150 °C

SYMBOL PARAMETER VALUE UNIT

R

th j-a

thermal resistance from junction to ambient in free air

TDA8574 (DIP16) 75 K/W
TDA8574T (SO16) 110 K/W