TDA8922C NXP Semiconductors, TDA8922C Datasheet - Page 11

• Manufacturer Part Number: TDA8922C
• Description: The TDA8922C is a high-efficiency Class D audio power amplifier
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA8922C_1
Product data sheet
8.3.4 Supply voltage protection
8.4 Differential audio inputs
If the supply voltage drops below the minimum supply voltage threshold, V
circuit will be activated and the system will shut down. Once the supply voltage rises
above V
If the supply voltage exceeds the maximum supply voltage threshold, V
circuit will be activated and the power stages will be shut down. When the supply voltage
drops below V
An additional UnBalance Protection (UBP) circuit compares the positive analog supply
voltage (on pin VDDA) with the negative analog supply voltage (on pin VSSA) and is
triggered if the voltage difference exceeds a factor of two (V
2
V
An overview of all protection circuits and their respective effects on the output signal is
provided in
Table 5.
[1]
[2]
[3]
The audio inputs are fully differential ensuring a high common mode rejection ratio and
maximum flexibility in the application.
Protection name Complete
TFB
OTP
OCP
WP
UVP
OVP
UBP
•
th(ubp)
V
Start-up will be interrupted If a short-circuit is detected between one of the output
terminals and pin VDDP1/VDDP2 or VSSP1/VSSP2. The TDA8922C will wait until the
short-circuit to the supply lines has been removed before resuming start-up. The short
circuit will not generate large currents because the short-circuit check is carried out
before the power stages are enabled.
When the amplifier is shut down completely because the OCP circuit has detected a
short circuit to one of the supply lines.
Section
lines has been removed.
Amplifier gain depends on the junction temperature and heatsink size.
The amplifier shuts down completely only if the short-circuit impedance is below the impedance threshold
(Z
Fault condition detected during any Standby-to-Mute transition or during a restart after OCP has been
activated (short-circuit to one of the supply lines).
[1]
WP will be activated when the amplifier attempts to restart after 100 ms (see
DDA
th
, the system restarts after 100 ms.
; see
th(uvp)
). When the supply voltage difference drops below the unbalance threshold,
Overview of TDA8922C protection circuits
Section
Table
8.3.2). The amplifier will not start-up again until the short circuit to the supply
again, the system will restart after a delay of 100 ms.
th(ovp)
5.
8.3.2). In all other cases, current limiting results in a clipped output signal.
shutdown
N
Y
Y
N
Y
Y
Y
[2]
[3]
again, the system will restart after a delay of 100 ms.
Rev. 01 — 7 September 2009
Restart directly
N
N
N
Y
N
N
N
[2]
Restart after
100 ms
N
Y
Y
N
Y
Y
Y
2
[2]
75 W class-D power amplifier
DDA
> 2
TDA8922C
V
© NXP B.V. 2009. All rights reserved.
th(ovp)
SSA
Pin PROT
detection
N
N
Y
N
N
N
N
th(uvp)
OR V
, the OVP
, the UVP
SSA
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