TA0103A Tripath Technology Inc., TA0103A Datasheet - Page 9

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

TA0103A Amplifier Operation
Figure 3 is a simplified diagram of one channel (channel 1) of a TA0103A amplifier to assist in
understanding its operation.
The audio input signal (IN1) is fed to the processor internal to the TA0103A, where a modulation
pattern is generated. This pattern is spread spectrum and varies between approximately 200kHz and
1.5MHz. Complementary copies of the switching pattern are level-shifted by the MOSFET drivers
and output from the TA0103A where they drive the gates (HO1 and LO1) of external power
MOSFETs that are connected as a half bridge. The output of the half bridge is a power-amplified
version of the switching pattern that switches between V
filtered to obtain amplified audio.
The processor portion of the TA0103A is operated from a 5-volt supply (between V5 and AGND). In
the generation of the complementary modulation pattern for the output MOSFETs, the processor
inserts a “break-before-make” dead time between when it turns one transistor off and it turns the other
one on in order to minimize shoot-through currents in the MOSFETs.
programmed by setting the break-before-make control bits, BBM0 and BBM1. Feedback information
from the output of the half-bridge is supplied to the processor via FDBKN1. Additional feedback
information to account for ground bounce is supplied via GNDKELVIN1.
Functional Description
9
C
IN
R
IN
Figure 3: Simplified TA0103A Amplifier
R
MUTE
OCR1
BBM0
BBM1
V5
OCR1
IN1
11
4
6
7
8
3
1
A Gnd
TA0103A
Processing
Modulation
Over/Under
&
Voltage
Over-current
Over-current
Detection
Detection
28
P Gnd
V
BOOT
17
13
14
24
18
16
22
21
19
20
35
23
15
9 GNDKELVIN1
2
LO1COM
OCS1H+
OCS1H-
HO1COM
FDBKN1
HO1
VN12
LO1
OCS1L+
OCS1L-
V
HMUTE
V
OVERLOADB
SNEG
SPOS
SPOS
R
R
G
G
and V
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
M
M
SNEG
R
R
S
S
V
. This signal is then low-pass
V
SNEG
SPOS
The dead time can be
TA0103 – Rev 3.3/06.00
Low-pass
Filter
R
L