TDA8571J/N2C,112

Overview

The TDA8571J is a quad bridge-tied load (BTL) power amplifier designed for automotive audio systems. It integrates four Class-B amplifiers with a fixed closed-loop voltage gain of 34 dB. The device delivers 4 × 40 W EIAJ output power into a 4 Ω load. Operating supply voltage ranges from 6 V to 18 V, with a typical quiescent current of 200 mA and standby current below 100 μA. It features an open-collector diagnostic output for distortion, short-circuit, and thermal warnings.

Feature Summary

• Integrated dynamic distortion detector, short-circuit protection, and temperature pre-warning via a single diagnostic pin.
• Three-mode operation including operating, mute, and standby states controlled by a low-current mode select switch.
• Robust protection against load dump, reverse polarity, and cross-load short circuits with low power dissipation during faults.

Applications

• Car radio power amplification
• Automotive speaker drive systems

Procurement Notes

Verify the specific ordering suffix matches the required package variant. Confirm the component status as production data or obsolete through official NXP channels before design finalization. Ensure PCB layout adheres to the specified ground separation guidelines to minimize crosstalk between the diagnostic output and signal inputs.

Selection Notes

Select this component for applications requiring high output power in a compact form factor with minimal external components. The fixed 34 dB gain simplifies circuit design but requires input signal levels to be compatible. Consider the thermal resistance characteristics and ensure adequate heat sinking for continuous high-power operation within the specified ambient temperature range.

Part Context

The TDA8571J belongs to the Philips/NXP car radio amplifier family. It is pin-compatible with the TDA8568Q, although the gain specification differs. This integration allows for simplified board layouts in automotive infotainment systems while maintaining high efficiency and robust fault protection mechanisms.

Replacement Considerations

The TDA8568Q is identified as a pin-compatible alternative, though users must account for differences in voltage gain specifications when substituting.

FAQ

How does the diagnostic pin indicate different fault conditions?

The open-collector VDIAG pin goes LOW to indicate dynamic distortion clipping, active short-circuits to ground/supply, or virtual junction temperatures reaching 145 °C.

What is the recommended procedure to prevent switch-on plops?

Keep the amplifier in mute mode for at least 150 ms to allow input capacitors to charge before switching to operating mode.