T E C H N I C A L I N F O R M A T I O N
Application Information
Layout Recommendations
The TA2024 is a power (high current) amplifier that operates at relatively high switching frequencies.
The outputs of the amplifier switch between the supply voltage and ground at high speeds while
driving high currents. This high-frequency digital signal is passed through an LC low-pass filter to
recover the amplified audio signal. Since the amplifier must drive the inductive LC output filter and
speaker loads, the amplifier outputs can be pulled above the supply voltage and below ground by the
energy in the output inductance. To avoid subjecting the TA2024 to potentially damaging voltage
stress, it is critical to have a good printed circuit board layout. It is recommended that Tripath’s layout
and application circuit be used for all applications and only be deviated from after careful analysis of
the effects of any changes. Please contact Tripath Technology for further information regarding
reference design material regarding the TA2024.
Amplifier Gain
The gain of the TA2024 is set by the ratio of two external resistors, RI and RF, and is given by the
following formula:
V
V
R
F
O
= 12
R
I
I
where VI is the input signal level and VO is the differential output signal level across the speaker.
9 Watts of RMS output power results from an 8.485V RMS signal across an 8Ω speaker load. If
RF = RI, then 9 Watts will be achieved with 0.707V RMS of input signal.
8.485VRMS
=
(RL ∗PO ) = (8Ω ∗ 9W)
Protection Circuits
The TA2024 is guarded against over-temperature and over-current conditions. When the device
goes into an over-temperature or over-current state, the FAULT pin goes to a logic HIGH state
indicating a fault condition. When this occurs, the amplifier is muted, all outputs are TRI-STATED,
and will float to 1/2 of VDD.
Over-temperature Protection
An over-temperature fault occurs if the junction temperature of the part exceeds approximately
155°C. The thermal hysteresis of the part is approximately 45°C, therefore the fault will automatically
clear when the junction temperature drops below 110°C.
Page 8
TA2024 Preliminary, Rev. 1.0
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
