Texas Instruments TPA3120D2 User Manual
User's Guide
SLOU189A – March 2007 – Revised April 2007
TPA3120D2 Audio Power Amplifier EVM
Contents
1 Introduction .......................................................................................... 2
2 Operation ............................................................................................ 3
3 TPA3120D2 EVM Schematic ..................................................................... 4
4 TPA3120D2 EVM PCB Layers ................................................................... 5
5 TPA3120D2 Evaluation Module Parts List ...................................................... 7
List of Figures
1 TPA3120D2 Audio Power Amplifier EVM ....................................................... 2
2 TPA3120D2 EVM Schematic ..................................................................... 4
3 Top Side Layout .................................................................................... 5
4 Bottom Side Layout ................................................................................ 6
List of Tables
1 TPA3120D2 EVM Specifications ................................................................. 2
2 Gain Settings ........................................................................................ 3
3 TPA3120D2 EVM Bill of Materials................................................................ 7
SLOU189A – March 2007 – Revised April 2007 TPA3120D2 Audio Power Amplifier EVM 1
Submit Documentation Feedback
www.ti.com
Introduction
1 Introduction
The TPA3120D2 evaluation module consists of a single 25-W, class-D, stereo audio power amplifier
complete with a small number of external components mounted on a circuit board that can be used to
directly drive speakers with an external analog audio source as the input.
Table 1. TPA3120D2 EVM Specifications
VALUE UNIT
V
CC
I
CC
P
O
Z
L
Supply voltage range 10 to 30 V
Supply current, maximum 2 A
Continuous output power, PO: 4 Ω , V
Minimum load impedance 3.2 Ω
= 27 V, THD+N = 10% 24 W
CC
Figure 1. TPA3120D2 Audio Power Amplifier EVM
TPA3120D2 Audio Power Amplifier EVM2 SLOU189A – March 2007 – Revised April 2007
Submit Documentation Feedback
www.ti.com
2 Operation
2.1 Quick Start List for Stand-Alone Operation
Follow these steps to use the TPA3120D2EVM stand-alone or when connecting it into existing circuits or
equipment. Connections to the EVM module can be made by inserting stripped wire, or using banana
plugs for the power supply and output connections. The inputs accept standard RCA plugs.
2.1.1 Power Supply
1. Ensure that all external power sources are set to OFF.
2. Connect an external regulated power supply adjusted from 10 V to 30 V to the module VCC (J7) and
GND (J8) banana jacks taking care to observe marked polarity.
2.1.2 Evaluation Module Preparations
Inputs and Outputs:
1. Connect an audio source to the input jacks, J9 and J10.
2. Connect a speaker across GND (J5) and +ROUT (J6). Connect another speaker across LOUT (J3)
and GND (J4)
3. Install both gain jumpers GAIN0 (J1) and GAIN1 (J2). This sets the gain of the amplifier to the lowest
level, 20 dB.
Control Inputs:
1. SHUTDOWN: This terminal is active LOW. A LOW on the device terminal (<0.8 V) shuts down the
amplifier; a HIGH (>2 V) on the device terminal places the amplifier in the active state. Holding down
switch SW1 places the amplifier in the SHUTDOWN state. Releasing SW1 returns the amplifier to the
active state. This terminal is V
2. MUTE: This terminal is active HIGH. A HIGH (>2 V) on this terminal will immediately terminate audio
playback through the speakers; a LOW (<0.8 V) enables the device. The outputs remain switching with
fifty percent duty cycle. SW2 on the EVM controls the state of the MUTE terminal. Holding down switch
SW2 places the amplifier in the MUTE state. Releasing SW2 returns the amplifier to the active state.
This terminal is V
3. GAIN0/GAIN1: Together, these terminals determine the gain of the amplifier. See Table 2 . Installing a
jumper in J1 or J2 sets the respective terminal to GND. Removing the jumper sets the respective
terminals to VCC. Removing jumpers increases the gain while installing jumpers decreases the gain.
Logic levels are TTL compatible. These terminals are V
4. Power-off Depop Circuit: Additional circuitry to quiet power-off pop has been provided on the EVM.
This circuit consists of shunt regulator D1, bipolar transistor Q4, and the surrounding components. This
circuit is activated by installing the jumper J11 which connects Vcc to the network. The depop circuit
has two different modes of operation. When R13 is installed, this circuit slowly pulls down the voltage
on the Bypass pin when power is removed resulting in a controlled reduction of the Class D output
duty cycle. If R17 is installed, the network reduces the pop by pulling down the shutdown pin at
power-off. This approach can be used if the power supply operates in such a way that there is a
significant time delay between removal of power and the point where Vcc falls below the chip UVLO
level, which is approximately 8 volts.
compliant.
CC
Operation
compliant.
CC
compliant.
CC
GAIN0 (J1) GAIN1 (J2) Amplifier Gain (dB)
ON ON 20
ON OFF 26
OFF ON 32
OFF OFF 36
SLOU189A – March 2007 – Revised April 2007 TPA3120D2 Audio Power Amplifier EVM 3
Submit Documentation Feedback
Table 2. Gain Settings
Loading...