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SHORT-CIRCUIT PROTECTION

THERMAL PROTECTION

PRINTED-CIRCUIT BOARD (PCB) LAYOUT

BASIC MEASUREMENT SYSTEM

TAS5601

SLAS585 – FEBRUARY 2008

The TAS5601 has short-circuit protection circuitry on the outputs that prevents damage to the device during

output-to-output shorts and output-to-GND shorts after the filter and output capacitor (at the speaker terminal.)

Directly at the device terminals, the protection circuitry prevents damage to device during output-to-output,

output-to-ground, and output-to-supply. When a short circuit is detected on the outputs, the part immediately

disables the output drive. This is latched fault and is cleared by cycling the RESET pin. Normal operation is

restored when the fault is removed.

The FAULT will transition low when a short is detected. The FAULT pin will be cleared after RESET is cycled.

Thermal protection on the TAS5601 prevents damage to the device when the internal die temperature exceeds

150

°C. There is a ±15°C tolerance on this trip point from device to device. Once the die temperature exceeds the

thermal set point, the device enters into the shutdown state and the outputs are disabled. This is not a latched

fault. The thermal fault is cleared once the temperature of the die is reduced by 20

°C. The device begins normal

operation at this point with no external system interaction.

Thermal protection fault is NOT reported on the FAULT terminal.

A THERM_WARN terminal can be used to monitor when the internal device temperature reaches 125

°C. The

terminal will transition low at this point and transition back high after the device cools approximately 20

°C. It is

not necessary to cycle RESET to clear this warning flag.

Because the TAS5601 is a class-D amplifier that switches at a high frequency, the layout of the printed-circuit

board (PCB) should be optimized according to the following guidelines for the best possible performance.

• Decoupling capacitors—The high-frequency 0.1-µF decoupling capacitors should be placed as close to the

PVCC and AVCC terminals as possible. The BYPASS capacitor and VCLAMP_XX capacitors should also be

placed as close to the device as possible. Large (220-

µF or greater) bulk power-supply decoupling capacitors

should be placed near the TAS5601 on the PVCCx terminals. For single-ended operation, a 220

µF capacitor

should be placed on each PVCC pin. For Bridge-tied operation, a single 220

µF, capacitor can be shared

between A and B or C and D.

• Grounding—The AVCC decoupling capacitor and BYPASS capacitor should each be grounded to analog

ground (AGND). The PVCCx decoupling capacitors and VCLAMP_xx capacitors should each be grounded to

power ground (PGND). Analog ground and power ground should be connected at the thermal pad, which

should be used as a central ground connection or star ground for the TAS5601.

• Output filter—The reconstruction LC filter should be placed as close to the output terminals as possible for the

best EMI performance. The capacitors should be grounded to power ground.

• Thermal pad—The thermal pad must be soldered to the PCB for proper thermal performance and optimal

reliability. The dimensions of the thermal pad and thermal land are described in the mechanical section at the

back of the data sheet. See TI Technical Briefs SLMA002 and SLOA120 for more information about using the

thermal pad. For recommended PCB footprints, see figures at the end of this data sheet.

For an example layout, see the TAS5601 Evaluation Module (TAS5601EVM) User Manual, (SLOU189). Both the

EVM user manual and the thermal pad application note are available on the TI Web site at http://www.ti.com.

This section focuses on methods that use the basic equipment listed below:

• Audio analyzer or spectrum analyzer

• Digital multimeter (DMM)

• Oscilloscope

• Twisted-pair wires

• Signal generator

• Power resistor(s)

• Linear regulated power supply

• Filter components

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Product Folder Link(s): TAS5601