TDA8932 View Datasheet(PDF) - NXP Semiconductors.

Part Name

Description

Manufacturer

TDA8932

Class-D audio amplifier

NXP Semiconductors. 

NXP Semiconductors

TDA8932

Class-D audio amplifier

• In case of a short to one of the supply lines, this will trigger the OCP and the amplifier

will be shut down. During restart the window protection will be activated. As a result

the amplifier will not start until 100 ms after the short to the supply lines is removed.

• In case of impedance drop (e.g. due to dynamic behavior of the loudspeaker) the

same protection will be activated. The maximum output current is again limited to 4 A,

but the amplifier will not switch off completely (thus preventing audio holes from

occurring). The result will be a clipping output signal without any artifacts.

8.4.4 Window Protection (WP)

The WP checks the PWM output voltage before switching from Sleep mode to Mute mode

(outputs switching) and is activated:

• During the start-up sequence, when pin POWERUP is switched from Sleep mode to

Mute mode. In the event of a short-circuit at one of the output terminals to VDDP1,

VSSP1, VDDP2 or VSSP2 the start-up procedure is interrupted and the TDA8932 waits for

open-circuit outputs. Because the check is done before enabling the power stages, no

large currents will flow in the event of a short-circuit.

• When the amplifier is completely shut down due to activation of the OCP because a

short-circuit to one of the supply lines is made, then during restart (after 100 ms) the

window protection will be activated. As a result the amplifier will not start until the

short-circuit to the supply lines is removed.

8.4.5 Supply voltage protection

If the supply voltage drops below 10 V, the UnderVoltage Protection (UVP) circuit is

activated and the system will shut down directly. This switch-off will be silent and without

pop noise. When the supply voltage rises above the threshold level, the system is

restarted again after 100 ms.

If the supply voltage exceeds 36 V the OverVoltage Protection (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 TDA8932. Two conditions

should be distinguished:

1. If the supply voltage is pumped to higher values by the TDA8932 application itself

(see also Section 14.3), the OVP is triggered and the TDA8932 is shut down. The

supply voltage will decrease and the TDA8932 is protected against any overstress.

2. If a supply voltage > 40 V is caused by other or external causes, then the TDA8932

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 voltage clamp.

An additional UnBalance Protection (UBP) circuit compares the positive analog supply

voltage (VDDA) and the negative analog supply voltage (VSSA) 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: VP(th)(ubp)l < 8⁄5 × VHVPREF

• HIGH-level threshold: VP(th)(ubp)h > 8⁄3 × VHVPREF

TDA8932_2

Preliminary data sheet

Rev. 02 — 12 December 2006

© NXP B.V. 2006. All rights reserved.

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