TDA8933B Datasheet, PDF (10/42 Pages) NXP Semiconductors – Class D audio amplifier

NXP Semiconductors
TDA8933B
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 enabled again as soon as the supply voltage drops below the threshold
level. The power stage is restarted after 100 ms.
Supply voltages > 40 V may damage the TDA8933B. Two conditions should be
distinguished here:
• If the supply voltage is pumped to higher values by the TDA8933B application itself
(see also Section 14.8), the OVP is triggered and the TDA8933B is shut down. The
supply voltage will decrease and the TDA8933B is thus protected against any
overstress.
• If a supply voltage > 40 V is caused by other or by external causes the TDA8933B will
shut down, but the device can still be damaged since the supply voltage in this case
will remain > 40 V. The OVP protection is not a supply clamp.
An additional UnBalance Protection (UBP) circuit compares the positive analog supply
voltage V_DDA with the negative analog supply voltage V_SSA and is triggered if the
difference between them exceeds a certain level. This level depends on the sum of both
supply voltages. The UBP 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 their effect on the output signal.
Table 6. Overview of protections for the TDA8933B
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
TDA8933B_1
Preliminary data sheet
Rev. 01 — 23 October 2008
© NXP B.V. 2008. All rights reserved.
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