C Controls to JP3............................................................................................... 6
1Bill of Materials for TPA2028D1YZFEVM .............................................................................. 10
1Introduction
1.1Description
The TPA2028D1 is a mono, filter-free Class-D audio power amplifier with automatic gain control (AGC),
dynamic range compression (DRC) and I2C digital volume control. The AGC and DRC functions enhance
the perceived audio loudness, and at the same time prevent speaker damage from overdrive. The
TPA2028D1 has independent software shutdown control and a 30-step volume control. Availability in the
WCSP package makes TPA2028D1 an ideal choice for both cellular handsets and PDAs.
The TPA2028D1 evaluation module (EVM) is a complete, stand-alone audio board. It contains the
TPA2028D1 WCSP (YZF) Class-D audio power amplifier.
Supply voltage range–0.3 V to 6 V
Supply current2 A Maximum
Continuous output power per channel, 8 Ω, Vdd = 5.0 V, THD + N = 10%1.7 W
Audio Input Voltage0.5 V to VDD- 0.5 V
2Operation
The TPA2028D1YZFEVM can be evaluated in a stand-alone mode or when connected to existing circuits
with I2C controls.
2.1Quick Start List for Stand-Alone Operation
A desktop or laptop computer with Windows™ XP installed is required in the stand-alone operation. Install
the software before connecting the EVM to a computer with a USB cable. The inputs accept standard
RCA plugs and the outputs accept banana connectors.
2.1.1Software Installation Sequence
1. Insert the CD provided.
2. Unzip the files to a temporary folder.
3. Install TPA2028D1 software by executing setup.exe located in TPA2028D1 Interface\.
Accept license agreement and defaults, and complete the installation. Note: you can uninstall later with
Add/Remove Programs.
NOTE:It is unnecessary to repeat the steps in Section 2.1.1, once the software is installed.
2.1.2Evaluation Module Preparations
1. Ensure that all external power sources are set to OFF.
2. Install shunt in jumper JP4;
3. Install shunts in jumpers JP2 when single-ended audio input is used; this ties IN– to ground.
4. Install shunts in J1 and J3 as shown in Figure 1. This sets the TPA2028D1 to accept I2C inputs from
the EVM itself.
Figure 1. Place Shunts Horizontally Across SDA and SCL
NOTE: The TPA2028D1 powers up with the amplifier in software shutdown. To hear an output,
uncheck shutdown.
3. Uncheck and check SPK_EN to place the Class-D output in and out of CHANNEL SHUTDOWN.
4. Click Shutdown to place the TPA2028D1 in and out of SOFTWARE SHUTDOWN.
5. Adjust the Attack Time, Release Time and Hold Time by sliding the bar or clicking the tap in the GUI.
You can also type a value in the box; in that case, the value will be rounded to the closest available
setting.
6. Adjust the Fixed Gain, Maximum Gain and Limiter Level by dragging the bar or clicking the tap in the
GUI. You can also type a value in the box; in that case, the value will be rounded to the closest
available setting.
7. Adjust Compression Ratio and Noise Gate Threshold by clicking the value.
8. The Limiter Power Level can be calculated by selecting the Load Resistance.
9. I2C Status box reports the status of I2C communications. An error or failure has occurred if it shows
I2C failure.
10. To read the I2C status, click Refresh.
11. Thermal box reports the status of thermal failure. A thermal fault has occurred if it turns red.
12. Click Show Graph to display the AGC transfer function. The transfer function is automatically updated
with the current AGC parameters (fixed gain, maximum gain, limiter level and compression) in GUI.
Click Hide Graph to hide the transfer function.
13. Volume Macro simulates volume control by changing fixed gain, limiter level and maximum gain
simultaneously. Follow the steps below to use the Volume Marco.
•At the top left corner of the GUI, select Volume Macro.
•Slide the volume bar to adjust the volume.
•Click Volume Marco again to go back to GUI.
•Click refresh to update the AGC parameters.
14. The GUI has a built-in I2C programming interface. Follow the steps below to use the I2C programming
function.
•At the top left corner of the GUI, click File to access the I2C programming interface.
•Save Script can record the current register values. Select Save Script >> Click the folder icon to
browse to the place where you want to save the script >> name the file in text format, then select
OK to save.
•Load Script can load the previously saved script to program the entire register file. Select Load
Script >> Click the folder icon to browse to the place where the script is located >> Select the file
then click OK >> Click Load.
•I2C interface can program individual register value of TPA2028D1. Select I2C Interface >> I2C
address is xB0, which is the address of TPA2028D1. Device address is from 1 to 7, which is the
register address of TPA2028D1.
2.1.4Shutdown Control
The TPA2028D1 EVM provides independent hardware shutdown controls for the Class-D power amplifier
and the USB controller.
1. Press and hold push button S1 to shutdown TPA2028D1. Release S1 to activate TPA2028D1.
2. Press and hold push button S2 to shutdown the USB controller. Release S2 to activate the USB
controller.
2.2Quick Start List When Connected to Existing Circuits With I2C Controls
The TPA2028D1YZFEVM can be easily connected to existing circuits with I2C controls. Connections to the
EVM module can be made using banana plugs for the power supply. The inputs accept standard RCA
plugs and the outputs accept banana connectors.
www.ti.com
2.2.1Evaluation Module Preparations
1. Ensure that all external power sources are set to OFF.
2. Install shunts in jumpers JP4.
3. Remove shunts between J1 and J3 and connect I2C controls to J1 as shown in Figure 5.
Figure 5. Connect I2C Controls to JP3
4. Install shunts in jumpers JP2 when single-ended audio input is used; this ties IN– to ground.
5. Remove USBPWR.
6. Connect an external regulated power supply adjusted for 2.5 V–5.5 V to the VDD and GND banana
jacks, taking care to observe marked polarity.
7. Connect audio source to IN.
8. Connect speakers (8 Ω to 32 Ω) to the output banana jacks OUTP and OUTM.
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:
This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES
ONLY and is not considered by TI to be a finished end-product fit for general consumer use. Persons handling the product(s) must have
electronics training and observe good engineering practice standards. As such, the goods being provided are not intended to be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including product safety and environmental
measures typically found in end products that incorporate such semiconductor components or circuit boards. This evaluation board/kit does
not fall within the scope of the European Union directives regarding electromagnetic compatibility, restricted substances (RoHS), recycling
(WEEE), FCC, CE or UL, and therefore may not meet the technical requirements of these directives or other related directives.
Should this evaluation board/kit not meet the specifications indicated in the User’s Guide, the board/kit may be returned within 30 days from
the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY SELLER TO BUYER
AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF
MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user indemnifies TI from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge.
EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY
INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
TI currently deals with a variety of customers for products, and therefore our arrangement with the user is not exclusive.
TI assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or
services described herein.
Please read the User’s Guide and, specifically, the Warnings and Restrictions notice in the User’s Guide prior to handling the product. This
notice contains important safety information about temperatures and voltages. For additional information on TI’s environmental and/or
safety programs, please contact the TI application engineer or visit www.ti.com/esh.
No license is granted under any patent right or other intellectual property right of TI covering or relating to any machine, process, or
combination in which such TI products or services might be or are used.
FCC Warning
This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES
ONLY and is not considered by TI to be a finished end-product fit for general consumer use. It generates, uses, and can radiate radio
frequency energy and has not been tested for compliance with the limits of computing devices pursuant to part 15 of FCC rules, which are
designed to provide reasonable protection against radio frequency interference. Operation of this equipment in other environments may
cause interference with radio communications, in which case the user at his own expense will be required to take whatever measures may
be required to correct this interference.
EVM WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the supply voltage range of –0.3 V to 6 V and the input voltage range of –0.3 V to VDD +0.3 .
Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM. If there are questions
concerning the input range, please contact a TI field representative prior to connecting the input power.
Applying loads outside of the specified output range may result in unintended operation and/or possible permanent damage to the EVM.
Please consult the EVM User's Guide prior to connecting any load to the EVM output. If there is uncertainty as to the load specification,
please contact a TI field representative.
During normal operation, some circuit components may have case temperatures greater than 85°C. The EVM is designed to operate
properly with certain components above 85°C as long as the input and output ranges are maintained. These components include but are
not limited to linear regulators, switching transistors, pass transistors, and current sense resistors. These types of devices can be identified
using the EVM schematic located in the EVM User's Guide. When placing measurement probes near these devices during operation,
please be aware that these devices may be very warm to the touch.