Texas Instruments PurePath TPA3251D2EVM User manual

User's Guide
SLVUAG8A–September 2015–Revised October 2015
TPA3251D2EVM
This user’s guide describes the operation of the evaluation module (TPA3251D2EVM) for the TPA3251D2
175-W Stereo/350-W mono PurePath™ Ultra-HD Analog Input Power Stage. The user’s guide also
provides design information, which includes schematic, BOM, and PCB layout. For questions and support
go to the E2E forums (e2e.ti.com).
The main contents of this document are:
• Hardware descriptions and implementation
• Design information
Related documents:
• TPA3251D2 Data Sheet (SLASE40)
Contents
1 Hardware Overview.......................................................................................................... 2
1.1 TPA3251D2EVM Features ........................................................................................ 2
1.2 TPA3251D2EVM Frequency Adjust.............................................................................. 3
1.3 TPA3251D2EVM Single-Ended and Differential Input......................................................... 3
1.4 TPA3251D2EVM Clip Overtemperature and Fault Indicators ................................................ 4
2 TPA3251D2EVM Setup..................................................................................................... 5
2.1 TPA3251D2EVM Setup............................................................................................ 5
2.2 Hardware Requirements........................................................................................... 5
2.3 Hardware Default Setup BTL (2.0) ............................................................................... 6
3 Using TPA3251D2EVM in Different Output Configurations............................................................ 7
3.1 BTL Plus Two SE (2.1) Operation................................................................................ 7
3.2 PBTL (0.1) Output Operation...................................................................................... 8
3.3 Single-Ended (SE) Output (4.0) Operation...................................................................... 8
4 Board Layouts, Bill of Materials, and Schematic ........................................................................ 9
4.1 TPA3251D2EVM Board Layouts ................................................................................. 9
4.2 TPA3251D2EVM Board Dimension............................................................................. 10
4.3 Bill of Materials .................................................................................................... 11
4.4 TPA3251D2EVM Schematic..................................................................................... 14
List of Figures
1 TPA3251D2EVM............................................................................................................. 2
2 TPA3251D2EVM Connections............................................................................................. 5
3 TPA3251D2EVM Top Composite Assembly............................................................................. 9
4 TPA3251D2EVM Bottom Composite Assembly ......................................................................... 9
5 TPA3251D2EVM Board Dimension...................................................................................... 10
6 TPA3251D2EVM Schematic.............................................................................................. 14
List of Tables
1 Frequency Adjust Master Mode Selection................................................................................ 3
2 Fault and Clip Overtemperature Status................................................................................... 4
3 Mode Selection Pins......................................................................................................... 7
4 Bill of Materials ............................................................................................................. 11
PurePath is a trademark of Texas Instruments.
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Hardware Overview www.ti.com
1 Hardware Overview
The TPA3251D2EVM PurePath™ Ultra-HD evaluation module demonstrates the TPA3251D2DDV
integrated circuit from Texas Instruments. The TPA3251D2DDV is a high-performance, high-power, class-
D amplifier that enables true premium sound quality with high efficiency class-D technology. It features an
advance integrated feedback design and high-speed gate driver error correction (PurePath Ultra-HD),
which enables ultra-low distortion across the audio band and superior audio quality. This EVM supports 2
BTL (stereo 2.0) output channels, 1 PBTL (mono 0.1) output channel, 1 BTL plus 2 SE (2.1) output
channels, and 4 SE (4.0) output channel configurations. The NE5532 is a high-performance audio op amp
designed to allow TPA3251D2DDV operation with differential or single-ended input signals to the EVM
with differential inputs yielding the optimal performance. TPA3251D2EVM is a complete 2 VRMS analog
input 2 × 175-W stereo/1 × 350-W mono high-power amplifier ready for evaluation and excellent listening
experience.
Figure 1. TPA3251D2EVM
1.1 TPA3251D2EVM Features
The TPA3251D2EVM has following features:
• Stereo PurePath Ultra-HD evaluation module
• Self-contained protection system (short circuit, clip, and thermal)
• Standard 2 VRMS differential input or single-ended line input
• BTL, PBTL, and SE output configuration support
• Frequency adjust and oscillator sync interface
• Single supply voltage range 18–38 V
• Double-sided, plated-through, 2-oz Cu, 2-layer PCB layout
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1.2 TPA3251D2EVM Frequency Adjust
The TPA3251D2EVM offers hardware trimmed oscillator frequency by external control of the FREQ_ADJ
pin. The Frequency adjust can be used to reduce interference problems while using a radio receiver tuned
within the AM band, the switching frequency can be changed from nominal to lower values. These values
should be chosen such that the nominal and the lower value switching frequencies together results in the
fewest cases of interference throughout the AM band. The oscillator frequency can be selected by the
value of the FREQ_ADJ resistor connected to GND in master mode according to Table 1.
Table 1. Frequency Adjust Master Mode Selection
Master Mode Resistor to GND
Nominal 10 kΩ
AM1 20 kΩ
AM2 30 kΩ
For slave-mode operation, turn off the oscillator by pulling the FREQ_ADJ pin to DVDD. This configures
the OSC_I/O pins as inputs to be slaved from an external differential clock. In a master/slave system inter-
channel delay is automatically setup between the switching phases of the audio channels, which can be
illustrated by no idle channels switching at the same time. This will not influence the audio output, but only
the switch timing to minimize noise coupling between audio channels through the power supply. This will
optimize audio performance and result in better operating conditions for the power supply. The inter-
channel delay will be setup for a slave device depending on the polarity of the OSC_I/O connection such
that slave mode 1 is selected by connecting OSC_I/O of the master device in phase with OSC_I/O of the
slave device (+ to + and – to –), while slave mode 2 is selected by connecting the OSC_I/O's out of phase
(+ to – and – to +).
1.3 TPA3251D2EVM Single-Ended and Differential Input
The TPA3251D2EVM supports both differential and single-ended inputs. For single-ended inputs, J4
and/or J19 jumpers are set to the SE position, so that the TPA3251D2EVM uses the NE5532 to convert
the single-ended input signal to differential to properly drive the differential inputs of the TPA3251D2. The
input RCA jack, J3, is used to provide INA and INB inputs and RCA jack J18 is used to provide INC and
IND inputs with single-ended inputs.
For differential input operation, J4 and/or J19 jumpers are set to the DIFF position, and the
TPA3251D2EVM uses the NE5532 to buffer the differential input signal to the differential inputs of the
TPA3251D2. The input RCA jack, J3, is used to provide INA, RCA jack J14 provides INB, RCA jack J18
provides INC, and RCA jack J15 provides IND with differential inputs.
NOTE: Single-ended input settings on the TPA3251D2EVM should only be used for channels with
output configuration BTL or PBTL, not SE. For SE output configuration J4 and/or J19
jumpers for that channel must be set to the DIFF position, so the input signal INx is mapped
directly to OUTx.
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1.4 TPA3251D2EVM Clip Overtemperature and Fault Indicators
The TPA3251D2EVM is equipped with LED indicators that illuminate when the FAULT and/or CLIP_OTW
pin goes low. See Table 2 and the TPA3251D2 data sheet (SLASE40) for more details.
Table 2. Fault and Clip Overtemperature Status
FAULT CLIP_OTW Description
Overtemperature (OTE) or overload (OLP) or undervoltage (UVP). Junction temperature higher
0 0 than 125°C (overtemperature warning).
Overload (OLP) or undervoltage (UVP). Junction temperature higher than 125°C (overtemperature
0 0 warning).
0 1 Overload (OLP) or undervoltage (UVP). Junction temperature lower than 125°C.
1 0 Junction temperature higher than 125°C (overtemperature warning)
1 1 Junction temperature lower than 125°C and no OLP or UVP faults (normal operation)
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3-3 V LED
SE A/B Input
DIFF A Input
Power Supply
Warning LEDs
SE C/D Input
DIFF C Input
DIFF B Input
TPS3251D2 Device
Under Heat Sink
DIFF D Input
RESET Switch
OUTB
OUTA
OUTD
OUTC
GND
www.ti.com TPA3251D2EVM Setup
2 TPA3251D2EVM Setup
This section describes the TPA3251D2EVM hardware setup and connection.
2.1 TPA3251D2EVM Setup
Figure 2 illustrates the TPA3251D2EVM connection.
Figure 2. TPA3251D2EVM Connections
2.2 Hardware Requirements
The following hardware is required for this EVM:
• TPA3251D2EVM (AIP025-001)
• Power supply 5–14 A/18–38 VDC
• Two 3–8 Ω(≈100 W) speakers/resistor loads
• Four speaker/banana cables
• RCA input cables
• Analog output audio source
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2.3 Hardware Default Setup BTL (2.0)
BTL (2.0) default hardware setup is as follows:
• Remove the EVM from the ESD bag.
• Check that jumpers are in their default state as shown in Figure 1 for stereo BTL operation:
– J4 and J19 pin 1-pin 2 position (SE Input)
– J5 and J6 pin 2-pin 3 position (2 BTL Output)
– J7, J8, J17, and J21 out
– J16 pin 3-pin 4 position (Master Mode)
– J22, J23, J24 and J25 in (BTL Outputs)
• Set S1 to the RESET position.
• Set power supply to 36 V (18- to 38-V range) and current to 10 A (5- to 14-A range). Do not power up
until all connections are completed.
• Connect power supply to TPA3251D2 EVM positive terminal to PVDD (RED) and negative terminal to
GND (BLACK).
• Connect left channel speaker/power resistor load (3–8 Ω) to TPA3251D2 EVM positive output terminal
to OUTA (RED) and AP analog input channel A positive terminal.
• Connect left channel speaker/power resistor load (3–8 Ω) to TPA3251D2 EVM negative output
terminal to OUTB (BLACK) and AP analog input channel A negative terminal.
• Connect right channel speaker/power resistor load (3–8 Ω) to TPA3251D2 EVM positive output
terminal to OUTC (RED) and AP analog input channel B positive terminal.
• Connect right channel speaker/power resistor load (3–8 Ω) to TPA3251D2 EVM negative output
terminal to OUTD (BLACK) and AP analog input channel B negative terminal.
• Be careful not to mix up PVDD and OUTA and OUTB terminals, since the colors are the same (RED).
• For single-ended stereo inputs, connect AP channel A XLR to RCA male jacks to female RCA jacks
input A/AB (RED) and AP channel B XLR to RCA male jacks to female RCA jacks input C/CD (WHITE)
and set J4 and J19 jumper positions to SE.
• For differential stereo inputs, connect positive RCA male jacks to female RCA jacks input A/AB
(RED) and input C/CD (WHITE) and connect negative RCA male jacks to female RCA jacks input B
(YELLOW) and input D (BLACK) and set J4 and J19 jumper positions to DIFF.
• Power up power supply once all the connections are made correctly and the 3.3-V LED (GREEN) will
illuminate.
• Set S1 to the NORMAL position.
• CLIP_OTWz (ORANGE) and FAULTz (RED) LEDs should be off, if the audio source is off.
NOTE: J3/J10 and J18/J15 can be used for differential inputs to INA/INB and INC/IND, respectively.
Using a smart phone/tablet/PC with headphone to RCA cable, audio streaming via headphone jack can
begin once the EVM is powered up correctly with jumpers in their default state. Start the media player of
your choice and enjoy the enhanced audio performance TPA3251D2 provides as a quick check of the
setup.
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3 Using TPA3251D2EVM in Different Output Configurations
The TPA3251D2EVM can be configured for four different output operations. The 2.0 BTL configuration is
the default set up of the TPA3251D2EVM described in Section 2.3. The remaining three configurations are
2.1 BTL plus two single-ended (SE) outputs, 0.1 PBTL output, and 4.0 single-ended (SE) outputs.
Table 3. Mode Selection Pins
Mode Pins Input Mode Output Configuration Description
M2 M1
0 0 2N + 1 2 × BTL Stereo BTL output configuration
0 1 2N/1N + 1 1 × BTL + 2 × SE 2.1 BTL + SE mode
Paralleled BTL configuration. Connect INPUT_C and INPUT_D to
1 0 2N + 1 1 × PBTL GND.
1 1 1N + 1 4 × SE Single-ended output configuration
3.1 BTL Plus Two SE (2.1) Operation
Configure the EVM as follows for 2 SE + 1 BTL operation:
• Set J6 to L and J5 to H.
• Connect left (stereo) speaker/power resistor load (2–4 Ω) positive terminal to OUTC and remove
jumper J24.
• Connect right (stereo) speaker/power resistor load (2–4 Ω) positive terminal to OUTD and remove
jumper J25.
• Connect subwoofer (mono) speaker/power resistor load (3–8 Ω) positive terminal to OUTA and
negative terminal to OUTB.
• Set J19 jumper position to DIFF.
• Connect left (stereo) channel input to female RCA jack input C/CD (WHITE) for OUTC speaker.
• Connect right (stereo) channel input to female RCA jack input D (BLACK) for OUTD speaker.
• For single-ended subwoofer (mono) input, connect RCA male jack to female RCA jack input A/AB
(RED) and set J4 jumper positions to SE.
• For differential subwoofer (mono) inputs, connect positive RCA male jack to female RCA jack input
A/AB (RED) and connect negative RCA male jack to female RCA jack input B (YELLOW) and set J4
jumper positions to DIFF.
NOTE: OUTC and OUTD are the single-ended output channels and OUTA and OUTB are the BTL
channel for 2.1 operations.
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3.2 PBTL (0.1) Output Operation
Configure the EVM as follows for PBTL operations:
• Set J6 to H and J5 to L.
• Connect speaker/power resistor (2–4 Ω) positive terminal to OUTA and OUTC (OUT A and C shorted).
• Connect speaker/power resistor (2–4 Ω) negative terminal to OUTB and OUTD (OUT B and D
shorted).
• Install PBTL jumpers J7 and J8 (pulls input C and input D to GND).
• For single-ended mono input, connect RCA male jack to female RCA jack input A/AB (RED) and set
J4 jumper positions to SE.
• For differential mono inputs, connect positive RCA male jack to female RCA jack input A/AB (RED)
and connect negative RCA male jack to female RCA jack input B (YELLOW) and set J4 jumper
position to DIFF.
NOTE: INA and INB are the inputs for PBTL and INC and IND are grounded for PBTL operation.
3.3 Single-Ended (SE) Output (4.0) Operation
Configure the EVM as follows for 4 single-ended operations:
• Set J6 to H and J5 to H.
• Connect speaker/power resistor (2–4 Ω) positive terminal to OUTA and remove jumper J22.
• Connect speaker/power resistor (2–4 Ω) positive terminal to OUTB and remove jumper J23.
• Connect speaker/power resistor (2–4 Ω) positive terminal to OUTC and remove jumper J24.
• Connect speaker/power resistor (2–4 Ω) positive terminal to OUTD and remove jumper J25.
• Set both J4 and J19 jumpers position to DIFF.
• Connect input to female RCA jack input A/AB (RED) for OUTA speaker.
• Connect input to female RCA jack input B (YELLOW) for OUTB speaker.
• Connect input to female RCA jack input C/CD (WHITE) for OUTC speaker.
• Connect input to female RCA jack input D (BLACK) for OUTD speaker.
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NOTE: The performance of the TPA3251D2EVM/TPA3251D2DDV is dependent on the power
supply. Design the power supply with margins that can deliver the needed power. In low-
frequency applications additional bulk capacitance may be needed. Replacing the bulk
capacitors on the TPA3251D2EVM with 3300 µF or more capacitance may be necessary,
depending on the power supply used.
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4 Board Layouts, Bill of Materials, and Schematic
4.1 TPA3251D2EVM Board Layouts
Figure 3 and Figure 4 illustrate the board layouts for the EVM.
Figure 3. TPA3251D2EVM Top Composite Assembly
Figure 4. TPA3251D2EVM Bottom Composite Assembly
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4.2 TPA3251D2EVM Board Dimension
Figure 5 illustrates the TPA3251D2EVM board dimensions 140 mm × 120 mm.
Figure 5. TPA3251D2EVM Board Dimension
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