T E C H N I C A L I N F O R M A T I O N
Over-current Protection
An over-current fault occurs if more than approximately 7 amps of current flows from any of the
amplifier output pins. This can occur if the speaker wires are shorted together or if one side of the
speaker is shorted to ground. An over-current fault sets an internal latch that can only be cleared if
the MUTE pin is toggled or if the part is powered down. Alternately, if the MUTE pin is connected to
the FAULT pin, the HIGH output of the FAULT pin will toggle the MUTE pin and automatically reset
the fault condition.
Overload
The OVERLOADB pin is a 5V logic output. When low, it indicates that the level of the input signal
has overloaded the amplifier resulting in increased distortion at the output. The OVERLOADB signal
can be used to control a distortion indicator light or LED through a simple buffer circuit, as the
OVERLOADB cannot drive an LED directly.
Sleep Pin
The SLEEP pin is a 5V logic input that when pulled high (>3.5V) puts the part into a low quiescent
current mode. This pin is internally clamped by a zener diode to approximately 6V thus allowing the
pin to be pulled up through a large valued resistor (1megΩ recommended) to VDD. To disable SLEEP
mode, the sleep pin should be grounded.
Fault Pin
The FAULT pin is a 5V logic output that indicates various fault conditions within the device. These
conditions include: low supply voltage, low charge pump voltage, low 5V regulator voltage, over
current at any output, and junction temperature greater than approximately 155°C. All faults except
overcurrent all reset upon removal of the condition. The FAULT output is capable of directly driving
an LED through a series 200Ω resistor. If the FAULT pin is connected directly to the MUTE input an
automatic reset will occur in the event of an over-current condition.
TA2024 Preliminary, Rev. 1.0
Page 9
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
