TA0103A Tripath Technology Inc., TA0103A Datasheet - Page 11

• Manufacturer Part Number: TA0103A
• Manufacturer: Tripath Technology Inc.

Application Information
Amplifier Gain and Input Resistor Selection
The value of the input resistor, R
according to:
Input Capacitor Selection
C
low-frequency pole. Typically this pole is set at 10 Hz. C
DC Offset Adjust
While the DC offset voltages that appear at the speaker terminals of a TA0103A amplifier are
typically small, Tripath recommends that any offsets during operation be nulled out of the amplifier
with a circuit like the one shown connected to IN1 and IN2 in the Test/Application Circuit.
It should be noted that the DC voltage on the output of a TA0103A amplifier with no load in mute
mode is approximately 2.5V. This offset does not need to be nulled. The output impedance of the
amplifier in mute mode is approximately 10 KOhms. This means that the 2.5V drops to essentially
zero when a typical load is connected.
Supply Voltage and Output Power
The relationship between the bipolar power supply voltage needed, V
power, P
by:
Typical measurement graphs of P
included in this data sheet to help determine the supply voltage.
11
IN
can be calculated once a value for R
A
where R
C
where:
R
F
V
where:
R
R
R
K = THD Factor, a number fixed by the algorithms in the TA0103A’s signal processor that
OUT
P
V
S
IN
IN
ON
COIL
S
= Input low frequency pole (typically 10Hz).
= 538 x10
= (2 x R
= Sense Resistor
= 1/((2S x F
= Input resistor value in ohms.
, into a given load, R
= The at-temperature R
provides the relationship between THD at full output power of the amplifier and V
corresponds to THD at full output power as follows:
= Resistance of the output filter inductor.
THD
0.1%
10%
IN
1%
= Input resistor value in ohms.
L
x P
3
/(R
P
OUT
)(R
IN
)
+ 5000)
IN
0.5
+ 5000))
/(K x R
0.83
0.95
1.09
L
K
, at a given level of THD (total harmonic distortion) is approximated
IN
OUT
DSON
, is based on the required voltage gain, A
L
/(R
versus supply voltage for various levels of THD are also
L
of the output transistors, M.
IN
+ R
has been determined. C
ON
+ R
S
+ R
IN
COIL
is calculated according to:
T r i p a t h T e c h n o l o g y , I n c . - T e c h n i c a l I n f o r m a t i o n
))
IN
and R
S
, for a given RMS output
TA0103 – Rev 3.3/06.00
IN
determine the input
V
, of the amplifier
S
. K