TDA8574 View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

TDA8574

Class-H high-output voltage level line driver

Philips Electronics 

Philips Semiconductors

Class-H high-output voltage level line

driver

Product specification

TDA8574

PINNING

SYMBOL

VCCL

INL

SVRL

INML

INMR

SVRR

INR

VCCR

CR+

CR−

RGND

OUTR

OUTL

LGND

CL−

CL+

PIN

DESCRIPTION

1

supply voltage left channel

2

input voltage left channel

3

SVRR left channel

4

inverting input left channel

5

inverting input right channel

6

SVRR right channel

7

input voltage right channel

8

supply voltage right channel

9

lift capacitor (+) right channel

10 lift capacitor (−) right channel

11 ground right channel

12 output voltage right channel

13 output voltage left channel

14 ground left channel

15 lift capacitor (−) left channel

16 lift capacitor (+) left channel

handbook, halfpage

VCCL 1

INL 2

16 CL+

15 CL−

SVRL 3

14 LGND

INML 4 TDA8574 13 OUTL

INMR 5 TDA8574T 12 OUTR

SVRR 6

11 RGND

INR 7

10 CR−

VCCR 8

9 CR+

MGE667

Fig.2 Pin configuration.

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 × VCC

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 Gv is

set by the feedback resistors according to the formula:

Gv = 1 + RR-----21-

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.

The DC output level is set to ≈0.87 × VCC. The maximum

peak-to-peak output voltage of the signal amplifier is

calculated with the formula:

Vo (p – p) max ≈ 2 × ( 0.87VCC – 0.4)

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.

1998 Oct 16

4

Share Link: