Datasheet

Protection Mechanisms in the TAS5602
Single-Ended Output Capacitor, C
O
Output Filter and Frequency Response
OUTA
L
filter
C
filter
L
filter
OUTB
C
filter
TAS5602
SLAS593B JUNE 2008 REVISED NOVEMBER 2008 ...................................................................................................................................................
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SCP (short-circuit protection, OCP) protects against shorts across the load, to GND, and to PVCC.
OTP turns off the device if T
die
(typical) > 150 ° C.
UVP turns off the device if PVCC (typical) < 8.4 V
OVP turns off the device if PVCC (typical) > 27.5 V
In single-ended (SE) applications, the dc blocking capacitor forms a high-pass filter with the speaker impedance.
The frequency response rolls of with decreasing frequency at a rate of 20 dB/decade. The cutoff frequency is
determined by:
f
c
= π C
O
Z
L
Table 1 shows some common component values and the associated cutoff frequencies:
Table 1. Common Filter Responses
C
SE
DC Blocking Capacitor ( µ F)
Speaker Impedance ( )
f
c
= 60 Hz ( 3 dB) f
c
= 40 Hz ( 3 dB) f
c
= 20 Hz ( 3 dB)
4 680 1000 2200
8 330 470 1000
For the best frequency response, a flat-passband output filter (second-order Butterworth) may be used. The
output filter components consist of the series inductor and capacitor to ground at the output pins. There are
several possible configurations, depending on the speaker impedance and whether the output configuration is
single-ended (SE) or bridge-tied load (BTL). Table 2 lists the recommended values for the filter components. It is
important to use a high-quality capacitor in this application. A rating of at least X7R is required.
Table 2. Recommended Filter Output Components
Output Configuration Speaker Impedance ( ) Filter Inductor ( µ H) Filter Capacitor (nF)
4 22 680
Single Ended (SE)
8 47 390
4 10 1500
Bridge Tied Load (BTL)
8 22 680
Figure 21. BTL Filter Configuration Figure 22. SE Filter Configuration
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