JAJSD67A April 2016 – November 2016 TPA3244
PRODUCTION DATA.
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NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
TPA3244 can be configured either in stereo BTL mode, 4 channel SE mode, mono PBTL mode, or in 2.1 mixed 1x BTL + 2x SE mode depending on output power conditions and system design.
This section provides an example for configuring the TPA3244 in bridge-tied load (BTL) mode.
For this design example, use the parameters in Table 6.
DESIGN PARAMETER | EXAMPLE |
---|---|
Low Power (Pull-up) Supply | 3.3 V |
Mid Power Supply 12 V | 12 V |
High Power Supply | 12 - 30 V |
Mode Selection | M2 = L |
M1 = L | |
Analog Inputs | INPUT_A = ±3.9 V (peak, max) |
INPUT_B = ± 3.9V (peak, max) | |
INPUT_C = ±3.9 V (peak, max) | |
INPUT_D = ±3.9 V (peak, max) | |
Output Filters | Inductor-Capacitor Low Pass FIlter (10 µH + 1 µF) |
Speaker Impedance | 3 - 8 Ω |
A rising-edge transition on reset input allows the device to execute the startup sequence and starts switching.
The CLIP signal is indicating that the output is approaching clipping. The signal can be used to either an audio volume decrease or intelligent power supply nominally operating at a low rail adjusting to a higher supply rail.
The device is inverting the audio signal from input to output.
The DVDD and AVDD pins are not recommended to be used as a voltage sources for external circuitry.
In order to design an amplifier that has robust performance, passes regulatory requirements, and exhibits good audio performance, good quality decoupling capacitors should be used. In practice, X7R should be used in this application.
The PVDD decoupling capacitors must be placed as close to the device pins a possible to insure short trace length and low a low inductance path. Likewise the ground path for these capacitors must provide a good reference and should be substantial. This will keep voltage ringing on PVDD to a minimum.
The voltage of the decoupling capacitors should be selected in accordance with good design practices. Temperature, ripple current, and voltage overshoot must be considered. This fact is particularly true in the selection of the 1μF that is placed on the power supply to each full-bridge. It must withstand the voltage overshoot of the PWM switching, the heat generated by the amplifier during high power output, and the ripple current created by high power output. A minimum voltage rating of 50 V is required for use with a 30V power supply.
The large capacitors used in conjunction with each full-bridge, are referred to as the PVDD Capacitors. These capacitors should be selected for proper voltage margin and adequate capacitance to support the power requirements. In practice, with a well designed system power supply, 1000 μF, 50 V supports most applications. The PVDD capacitors should be low ESR type because they are used in a circuit associated with high-speed switching.
FR-4 Glass Epoxy material with 2 oz. (70 μm) copper is recommended for use with the TPA3244 device. The use of this material can provide for higher power output, improved thermal performance, and better EMI margin (due to lower PCB trace inductance.
The built in oscillator frequency can be trimmed by an external resistor from the FREQ_ADJ pin to GND. Changes in the oscillator frequency should be made with resistor values specified in Recommended Operating Conditions while RESET is low.
To reduce interference problems while using a radio receiver tuned within the AM band, the switching frequency can be changed from nominal to lower or higher values. These values should be chosen such that the nominal and the alternate switching frequencies together result 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.
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 set up between the switching 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. Inter-channel delay is needed to optimize audio performance and to get better operating conditions for the power supply. The inter-channel delay will be set up for a slave device depending on the polarity of the OSC_I/O connection as follows:
The interchannel delay for interleaved channel idle switching is given in the table below for the master/slave and output configuration modes in degrees relative to the PWM frame.
Master | M1 = 0, M2 = 0, 2 x BTL mode | M1 = 1, M2 = 0, 1 x BTL + 2 x SE mode | M1 = 0, M2 = 1, 1 x PBTL mode | M1 = 1, M2 = 1, 4 x SE mode |
---|---|---|---|---|
OUT_A | 0° | 0° | 0° | 0° |
OUT_B | 180° | 180° | 180° | 60° |
OUT_C | 60° | 60° | 0° | 0° |
OUT_D | 240° | 120° | 180° | 60° |
Slave 1 | ||||
OUT_A | 60° | 60° | 60° | 60° |
OUT_B | 240° | 240° | 240° | 120° |
OUT_C | 120° | 120° | 60° | 60° |
OUT_D | 300° | 180° | 240° | 120° |
Slave 2 | ||||
OUT_A | 30° | 30° | 30° | 30° |
OUT_B | 210° | 210° | 210° | 90° |
OUT_C | 90° | 90° | 30° | 30° |
OUT_D | 270° | 150° | 210° | 90° |
Relevant performance plots for the TPA3244 device shown in are shown in BTL Configuration.
PLOT TITLE | FIGURE NUMBER |
---|---|
Total Harmonic Distortion+Noise vs Frequency | Figure 1 |
Total Harmonic Distortion+Noise vs Frequency, 80kHz analyzer BW | Figure 2 |
Total Harmonic Distortion + Noise vs Output Power | Figure 3 |
Output Power vs Supply Voltage, 10% THD+N | Figure 4 |
Output Power vs Supply Voltage, 10% THD+N | Figure 6 |
System Efficiency vs Output Power | Figure 6 |
System Power Loss vs Output Power | Figure 7 |
Output Power vs Case Temperature | |
Noise Amplitude vs Frequency | Figure 8 |
This section provides an example for configuring the TPA3244 in single-ended output (SE) mode.
For this design example, use the parameters in Table 9.
DESIGN PARAMETER | EXAMPLE |
---|---|
Low Power (Pull-up) Supply | 3.3 V |
Mid Power Supply 12 V | 12 V |
High Power Supply | 12 - 30 V |
Mode Selection | M2 = H |
M1 = H | |
Analog Inputs | INPUT_A = ±3.9 V (peak, max) |
INPUT_B = ±3.9 V (peak, max) | |
INPUT_C = ±3.9 V (peak, max) | |
INPUT_D = ±3.9 V (peak, max) | |
Output Filters | Inductor-Capacitor Low Pass FIlter (15 µH + 680 nF) |
Speaker Impedance | 2 - 8 Ω |
Relevant performance plots for TPA3244 shown in SE Configuration.
PLOT TITLE | FIGURE NUMBER |
---|---|
Total Harmonic Distortion + Noise vs Output Power | Figure 3 |
Total Harmonic Distortion+Noise vs Frequency | Figure 1 |
Total Harmonic Distortion+Noise vs Frequency, 80kHz analyzer BW | Figure 2 |
Output Power vs Supply Voltage, 10% THD+N | Figure 4 |
Output Power vs Supply Voltage, 10% THD+N | Figure 6 |
Output Power vs Case Temperature |
TPA3244 can be configured in mono PBTL mode by paralleling the outputs before the LC filter or after the LC filter (see Typical Application, Differential (2N), PBTL (Outputs Paralleled after LC filter)). Paralleled outputs before the LC filter is recommended for better performance and limiting the number of output LC filter inductors, only two inductors required. This sections shows an example of paralleled outputs before the LC filter.
For this design example, use the parameters in Table 11.
DESIGN PARAMETER | EXAMPLE |
---|---|
Low Power (Pull-up) Supply | 3.3 V |
Mid Power Supply 1 2V | 12 V |
High Power Supply | 12 - 30 V |
Mode Selection | M2 = H |
M1 = L | |
Analog Inputs | INPUT_A = ±3.9 V (peak, max) |
INPUT_B = ±3.9 V (peak, max) | |
INPUT_C = ±3.9 V (peak, max) | |
INPUT_D = ±3.9 V (peak, max) | |
Output Filters | Inductor-Capacitor Low Pass FIlter (10 µH + 1 µF) |
Speaker Impedance | 2 - 4 Ω |
Relevant performance plots for TPA3244 shown in PBTL Configuration.
PLOT TITLE | FIGURE NUMBER |
---|---|
Total Harmonic Distortion + Noise vs Output Power | Figure 3 |
Total Harmonic Distortion+Noise vs Frequency | Figure 1 |
Total Harmonic Distortion+Noise vs Frequency, 80kHz analyzer BW | Figure 2 |
Output Power vs Supply Voltage, 10% THD+N | Figure 4 |
Output Power vs Supply Voltage, 10% THD+N | Figure 6 |
Output Power vs Case Temperature |
TPA3244 can be configured in mono PBTL mode by paralleling the outputs before the LC filter (see Typical Application, Differential (2N), PBTL (Outputs Paralleled before LC filter)) or after the LC filter. Paralleled outputs after the LC filter may be preferred if: a single board design must support both PBTL and BTL, or in the case multiple, smaller paralleled inductors are preferred due to size or cost. Paralleling after the LC filter requires four inductors, one for each OUT_x. This section shows an example of paralleled outputs after the LC filter.
For this design example, use the parameters in Table 13.
DESIGN PARAMETER | EXAMPLE |
---|---|
Low Power (Pull-up) Supply | 3.3 V |
Mid Power Supply 12 V | 12 V |
High Power Supply | 12 - 30 V |
Mode Selection | M2 = H |
M1 = L | |
Analog Inputs | INPUT_A = ±3.9V (peak, max) |
INPUT_B = ±3.9V (peak, max) | |
INPUT_C = Grounded | |
INPUT_D = Grounded | |
Output Filters | Inductor-Capacitor Low Pass FIlter (10 µH + 1 µF) |
Speaker Impedance | 2 - 4 Ω |
Relevant performance plots for TPA3244 shown in PBTL Configuration.
PLOT TITLE | FIGURE NUMBER |
---|---|
Total Harmonic Distortion + Noise vs Output Power | Figure 3 |
Total Harmonic Distortion+Noise vs Frequency | Figure 1 |
Total Harmonic Distortion+Noise vs Frequency, 80kHz analyzer BW | Figure 2 |
Output Power vs Supply Voltage, 10% THD+N | Figure 4 |
Output Power vs Supply Voltage, 10% THD+N | Figure 6 |
Output Power vs Case Temperature |