TDA8576T Datasheet, PDF (4/16 Pages) NXP Semiconductors – Class-H high-output voltage level line driver

Philips Semiconductors
Class-H high-output voltage level line
driver
Product specification
TDA8576T
PINNING
SYMBOL
V_CCL
INL
SVRL
INML
INMR
SVRR
INR
V_CCR
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
13 OUTL
TDA8576T
INMR 5
12 OUTR
SVRR 6
11 RGND
INR 7
10 CR−
VCCR 8
9 CR+
MGE670
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 6 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 V_CC. 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:
G_v = 1 + ^RR-----21-
and should be set to 6 dB. The LIFT AMP. and SIGNAL
AMP. must have equal voltage gain G_v.
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 × V_CC. The maximum
peak-to-peak output voltage of the signal amplifier is
calculated with the formula:
V_{o (p – p) (max)} ≈ 2 × ( 0.87V_CC – 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