Datasheet

TAS5631B

SLES263C –NOVEMBER 2010–REVISED SEPTEMBER 2012

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SYSTEM DESIGN CONSIDERATIONS

A rising-edge transition on the reset input allows the device to execute the startup sequence and start switching.

Apply only audio 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.

Click and Pop in SE-Mode

The BTL startup has low click and pop due to the trimmed output dc offset, see the AUDIO CHARACTERISTICS

(BTL) table.

The startup of the BTL+2 x SE system (Figure 17) or 4xSE (Figure 16) is more difficult to get click and pop free,

than the pure BTL solution; therefore, evaluating the resulting click and pop before designing in the device is

recommended.

PBTL Overload and Short Circuit

The TAS5631B has extensive overload and short circuit protection. In BTL and SE mode, it is fully protected

against speaker terminal overloads, and terminal-to-terminal short circuit, and short circuit to GND or PVDD. The

protection works by limiting the current, by flipping the state of the output MOSFET’s; thereby, ramping currents

down in the inductor. This only works when the inductor is NOT saturated, the recommended minimum inductor

values are listed in RECOMMENDED OPERATING CONDITIONS table. In BTL mode, the short circuit currents

can reach more than 15A, so when connecting the device in PBTL mode (Mono), the currents double – that is

more than 30 A, and with these high currents, the protection system will limit PBTL speaker overloads, terminal-

to-terminal shorts, and terminal-to-GND shorts. PBTL mode short circuit to PVDD is not recommended.

PRINTED CIRCUIT BOARD RECOMMENDATION

Use an unbroken ground plane to have good low-impedance and -inductance return path to the power supply for

power and audio signals. PCB layout, audio performance and EMI are linked closely together. The circuit

contains high, fast-switching currents; therefore, care must be taken to prevent damaging voltage spikes. Routing

for the audio input should be kept short and together with the accompanying audio source ground. It is important

to keep a solid local ground area underneath the device to minimize ground bounce. It is always good practice to

follow the EVM layout as a guideline,

Netlist for this printed circuit board is generated from the schematic in Figure 15.

Product Folder Links: TAS5631B