Hardware Configuration
11
SLAU754A – January 2018 – Revised August 2019
Copyright © 2018–2019, Texas Instruments Incorporated
TPA3220 Evaluation Module
3.3
Modulation Modes (AD Mode and HEAD Mode)
The TPA3220EVM supports both AD modulation as well as HEAD modulation. In AD mode, each of the
two half-bridge outputs are continuously switching. AD mode is the default mode for the TPA3220EVM.
The EVM also supports HEAD mode modulation. HEAD mode also switches both half bridge outputs but
also optimizes the switching for lower power loss at idle as well as increased EMI performance at cost of
some performance. The device accomplishes this by reducing its duty cycle at idle and while playing small
signals. At higher output levels HEAD mode will also reduce the switching on one of the half bridges. The
modulation mode can be controlled through jumper J6 on the EVM as follows:
Table 5. HEAD and AD Mode Selection
J6 Jumper State
Modulation Mode
IN
AD Mode
OUT
HEAD Mode
More information on the differences between HEAD mode and AD mode as well as performance data is
found in
TPA3220 100-W Peak HD-Audio, Analog-Input, Class-D
.
3.4
Output Mode Selection
The TPA3220 does not use discrete mode pins and therefore relies solely on the states of the IN2_M and
IN2_P pins. Connecting the IN2_M and IN2_P pins to regular high output impedance audio outputs by
removing J7 and J8 puts the TPA3220 into BTL mode (2 x stereo outputs). Tying the IN2_M and IN2_P
pins to GND by installing J7 and J8 puts the TPA3220 into PBTL mode (1 x mono output). This is
summarized in
Table 6. Output Mode and Modulation Mode Selection
Input Jumpers
J7 and J8
Input Mode
Output
Configuration
Description
IN2_M
IN2_P
OUT
OUT
1N / 2N + 1
2 × BTL
Stereo BTL output configuration
IN
IN
1 × PBTL
Mono paralleled BTL configuration. Connect OUT1+ to OUT2+ and
OUT1– to OUT2–.
3.5
Audio Front End
The TPA3220EVM includes options for single-ended or differential input signals. A configurable front end
is built into the TPA3220 so that both single-ended and differential inputs can achieve the full scale output
of the TPA3220 device without need for external front end op-amp. Note that when EVM RCA or XLR
connectors are used, jumpers J11, J10, J21, and J20 must be installed in position 1:2 named
XLR
or
RCA
.
•
Single-ended input can be provided through RCA to inputs J3 and J18. Uninstall jumpers J4 and J12
using SE input so that the TPA3220 front-end will be configured for SE input.
•
Differential input can be provided through XLR to inputs J14 and J15. Install jumpers J4 and J12 when
using DIFF input so that the TPA3220 front-end will be configured for DIFF input.
Input can also be provided through an audio plug-in board on J28. For this input type, change jumpers
J11, J10, J21, and J20 to position 2:3 named
AIB
.
See the EVM schematic section (
) for complete details.