Datasheet

TAS5631B
SLES263C –NOVEMBER 2010–REVISED SEPTEMBER 2012 www.ti.com
ERROR REPORTING
The SD, OTW, OTW1, and OTW2 pins are active-low, open-drain outputs. Their function is for protection-mode
signaling to a PWM controller or other system-control device.
Any fault resulting in device shutdown is signaled by the SD pin going low. Likewise, OTW and OTW2 go low
when the device junction temperature exceeds 125°C and OTW1 goes low when the junction temperature
exceeds 100°C (see the following table).
OTW2,
SD OTW1 DESCRIPTION
OTW
0 0 0 Overtemperature (OTE) or overload (OLP) or undervoltage (UVP)
Overload (OLP) or undervoltage (UVP). Junction temperature higher than 100°C (overtemperature
0 0 1
warning)
0 1 1 Overload (OLP) or undervoltage (UVP)
1 0 0 Junction temperature higher than 125°C (overtemperature warning)
1 0 1 Junction temperature higher than 100°C (overtemperature warning)
1 1 1 Junction temperature lower than 100°C and no OLP or UVP faults (normal operation)
NOTE
Aasserting RESET low forces the SD signal high, independent of faults being present. TI
recommends monitoring the OTW signal using the system microcontroller and responding
to an overtemperature warning signal by, e.g., turning down the volume to prevent further
heating of the device resulting in device shutdown (OTE).
To reduce external component count, an internal pullup resistor to 3.3 V is provided on both SD and OTW
outputs. Level compliance for 5-V logic can be obtained by adding external pullup resistors to 5 V (see the
Electrical Characteristics table of this data sheet for further specifications).
DEVICE PROTECTION SYSTEM
The TAS5631B contains advanced protection circuitry carefully designed to facilitate system integration and ease
of use, as well as to safeguard the device from permanent failure due to a wide range of fault conditions such as
short circuits, overload, overtemperature, and undervoltage. The TAS5631B responds to a fault by immediately
setting the power stage in a high-impedance (Hi-Z) state and asserting the
SD
pin low. In situations other than
overload and overtemperature error (OTE), the device automatically recovers when the fault condition has been
removed, i.e., the supply voltage has increased.
The device functions on errors, as shown in the following table.
BTL Mode PBLT Mode SE Mode
Local Error In Turns Off Local Error In Turns Off Local Error In Turns Off
A A A
A + B A + B
B B B
A + B + C + D
C C C
C + D C + D
D D D
Bootstrap UVP does not shut down according to the table; it shuts down the respective half-bridge.
NOTE
In PBTL mode the device is protected against overload and load shorts, but shorting to
GND or PVDD during high load is not recommended
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