Tri path Technol og y, I nc. - Techni cal I nformation
of placing the output inductors close to the TA2024B output pins is to reduce the trace length of
the switching outputs. This will aid in reducing radiated emissions.
Please see the External Component Description section on page 6 for more details on the above-
mentioned components. The Application/ Test Circuit refers to the low side diodes as D
O
, The
high side diodes as D
H
, and both supply decoupling capacitors as C
SW
.
TA2024B Amplifier Gain
The ideal gain of the TA2024B is set by the ratio of two external resistors, R
I
and R
F
, and is given
by the following formula:
V
O
R
= −
12
F
V
I
R
I
where V
I
is the input signal level and V
O
is the differential output signal level across the speaker.
Please note that V
O
is 180° out of phase with V
I
.
The ideal gain of the TA2024B is 12V/V, whereas typical values are: A
V
= 11.5V/V for 4
Ω
and
11.7V/V for 8
Ω
.
Protection Circuits
The TA2024B 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 V
DD
.
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.
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 (1meg
Ω
recommended) to V
DD
. To disable
SLEEP mode, the sleep pin should be grounded.
9
TA2024B –KL/1.2/01.06
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
