TDA7572 Datasheet, PDF (43/64 Pages) STMicroelectronics – 200W mono bridge PWM amplifier with built-in step-up converter

TDA7572
Modulator
consists in a clipping of current when the first threshold for V_DS is trespassed. It is obtained
by sink or source current to the virtual ground of modulator integrator. The cycle-by-cycle
limitation is a strong limitation. If the second V_DS threshold is trespassed for more than
about 2µs the half bridge is tri-stated. If this condition persists for more then four PWM
periods the modulator is definitely tri-stated. It is possible setting the threshold V_DS voltage
for the current limiting by the pin IlimitThreshold: the first threshold is the value voltage value
of this pin (referred to VN2.5), the second one is the same value multiply by the factor 1.5.
7.2
ANTI-POP shunt driver
The device is provided by a driver able to control an anti-pop shunt MOS which is
connectable in series or in parallel to the load. During the mute-to-play or play-to-mute
transition an external MOS is able to disconnect (MOS in series) or short (MOS in parallel)
the speaker in order to reduce the audible pop noise.
The shunt driver is able to source or sink a predefined current (see Table 17). The following
diagram reports the temporal behave of current at the shunt pin respect to the voltage on the
mute pin in NOI²CBUS mode.
Figure 6. Current sourced by the shunt pin in NO I²Cbus mode
Vmute
Vsd+Vsdh
Isource
AC00018
In I²Cbus mode it is possible to change the driver current direction only by change the bit D0
of byte 5. When the bit is set to 1 the current is sourced. By default the current is sourced.
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