TS4621E

Application information

Doc ID 022201 Rev 1

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4.1.3

Control register CR1 - address 1

Amplifier output short-circuit detection: bits SC_L and SC_R

The amplifier’s outputs are protected from short-circuits that might accidentally occur during

manipulation of the device. In a typical application, if a short-circuit arises on the jack plug,

there will be no detection because of the serial resistor present on the amplifier output, thus

the output current threshold will not be reached.

To be active, the detection has to occur directly on the amplifier’s output with a signal

modulation on the inputs of the TS4621E. This detection is depicted in Figure 74.

Figure 74.

Flowchart for short-circuit detection

If a short-circuit is detected three consecutive times on one channel, a flag is raised in the

I²C read register CR1.

●

SC_L: equals 0 during normal operation, equals 1 when a short-circuit is detected on

the left channel.

●

SC_R: equals 0 during normal operation, equals 1 when a short-circuit is detected on

the right channel.

The corresponding channel’s output stage is then set to high impedance mode. An I²C read

command allows the reading of the SC_L and SC_R flags but does not reset them. An I²C

write command has to be sent to CR1 to reset the flags to 0 and restore normal operation.

AM06117

Counter = 0

TS4621E power OFF

Counter = counter + 1

TS4621E power ON

Timeout = 40 ms

TS4621E power ON

Wait 40 ms

Set flag SC_L or SC_R to 1

Set flag HiZ_L or HiZ_R to 1

Shortcut detection

Shortcut detection

Shortcut detection & timeout = 0

Shortcut detection

Reset

Counter < 3

Counter = 3