SLES217D November 2010 – March 2015 TAS5630B
PRODUCTION DATA.
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.
TI recommends FR-4 2-oz. (70-μm) glass epoxy material for use with the TAS5630B. The use of this material can provide for higher power output, improved thermal performance, and better EMI margin (due to lower PCB trace resistance).
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, 63-V supports more applications. The PVDD capacitors should be the low-ESR type, because they are used in a circuit associated with high-speed switching.
To design an amplifier that has robust performance, passes regulatory requirements, and exhibits good audio performance, quality decoupling capacitors should be used. In practice, X7R should be used in this application.
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 2.2-μF capacitor that is placed on the power supply to each half-bridge. The decoupling capacitor 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 63 V is required for use with a 50-V power supply.
A rising-edge transition on the reset input allows the device to execute the startup sequence and starts switching.
Apply audio only when the state of READY is high; that starts and stops the amplifier without having audible artifacts that are heard in the output transducers. If an overcurrent protection event is introduced, the READY signal goes low; hence, filtering is needed if the signal is intended for audio muting in non-microcontroller systems.
The CLIP signal indicates that the output is approaching clipping. The signal can be used either to activate a volume decrease or to signal an intelligent power supply to increase the rail voltage from low to high for optimum efficiency.
The device inverts the audio signal from input to output.
The VREG pin is not recommended to be used as a voltage source for external circuitry.
The following schematics and PCB layouts illustrate best practices used for the TAS5630B.
This device can be configured for BTL, PBTL, or SE mode. Each mode will require a different output configuration.
BTL output and differential input configuration is a typical audio class-D (PWM) amplifier. With differential input, the output can be configured for BTL application with BD modulation. The configuration below can also be used with AD modulation. BD modulation gives better channel separation and PSSR performance.
When there is a need for more power in an audio system, PBTL is a good choice for this application. Paralleling the output after the inductors is recommended. In this configuration, the device can be driven with higher current (lower load impedance). Figure 19 shows the component and pin connections.
Single-ended output configuration is often used for cost effective systems. This device can be configured to drive four independent channels with four different inputs. The delivered power is not as much as BTL configuration. The advantage is that the component count for four channels is the same as two BTL channels. The schematic in this section shows the component and pin connections.
One of the attractive features of this device is that it can be configured for mixed BTL and SE outputs. One BTL plus two SE channels make up a 2.1 audio system. While the SE channels are used to drive the front end and right speakers, the BTL channel can deliver higher power and is used to drive a subwoofer. Figure 21 shows the component and pin connections.
This is the same application as described in Typical Differential-Input BTL Application With BD Modulation Filters with PHD package. For DKD package an external heatsink is required to dissipate excess heat. In this package, the PCB space is not a limiting factor for dissipating excess heat.