TDA8933 Datasheet, PDF (11/47 Pages) NXP Semiconductors – Class-D audio amplifier

NXP Semiconductors
TDA8933
Class-D audio amplifier
If the supply voltage exceeds 36 V, the OVP circuit is activated and the power stages will
shut down. It is re-enabled as soon as the supply voltage drops below the threshold level.
The system is restarted again after 100 ms.
It should be noted that supply voltages > 40 V may damage the TDA8933. Two conditions
should be distinguished:
• If the supply voltage is pumped to higher values by the TDA8933 application itself
(see also Section 14.8), the OVP is triggered and the TDA8933 is shut down. The
supply voltage will decrease and the TDA8933 is protected against any overstress.
• If a supply voltage > 40 V is caused by other or external causes, the TDA8933 will
shut down, but the device can still be damaged since the supply voltage will remain
> 40 V in this case. The OVP protection is not a supply clamp.
An additional UBP circuit compares the positive analog supply voltage (V_DDA) and the
negative analog supply voltage (V_SSA) and is triggered if the voltage difference between
them exceeds a certain level. This level depends on the sum of both supply voltages. The
unbalance threshold levels can be defined as follows:
• LOW-level threshold: V_P(th)(ubp)l < 8/5 × V_HVPREF
• HIGH-level threshold: V_P(th)(ubp)h > 8/3 × V_HVPREF
In a symmetrical supply the UBP is released when the unbalance of the supply voltage is
within 6 % of its starting value.
Table 6 shows an overview of all protections and the effect on the output signal.
Table 6. Overview of protections for the TDA8933
Protection
Restart
When fault is removed
OTP
no
OCP
yes
WP
yes
UVP
no
OVP
no
UBP
no
Every 100 ms
yes
no
no
yes
yes
yes
TDA8933_1
Preliminary data sheet
Rev. 01 — 15 May 2007
© NXP B.V. 2007. All rights reserved.
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