TFA9842BJ/N1,112

Overview

The TFA9842BJ is a two-channel audio power amplifier designed for single-ended operation with a fixed voltage gain of 26 dB. It operates within a supply voltage range of 9 V to 26 V and delivers up to 7.5 W output power at THD=10% into a 4 Ω load. The device features low standby current, high supply voltage ripple rejection, and comprehensive protection against short circuits and thermal overload.

Feature Summary

• Integrated unique protection circuit based on multiple internal temperature measurements to maximize output power without unnecessary audio holes.
• Supports soft clipping and eliminates switching pops during on/off transitions.
• Includes dedicated standby and mute modes with very low current consumption.
• Outputs are protected against short circuits to ground, supply, and across the load.

Applications

• Televisions
• Monitors
• PC speakers
• Boom boxes
• Mini and micro audio receivers

Procurement Notes

Verify component authenticity through authorized distributors or NXP Semiconductors channels. Confirm package integrity and pin alignment prior to installation. Review the latest datasheet revision history for any specification updates. Ensure compliance with environmental directives such as EU RoHS and REACH SVHC requirements before integration.

Selection Notes

Select this component for applications requiring dual single-ended audio amplification with fixed gain. Evaluate thermal management requirements based on ambient temperature and load impedance. Consider pin compatibility with TFA9841J, TFA9842J, TFA9843J, and TFA9843BJ for potential design swaps. Verify supply voltage stability to ensure optimal ripple rejection performance.

Part Context

The TFA9842BJ belongs to a family of audio power amplifiers from Philips/NXP Semiconductors. It shares pin compatibility with related models like the TFA9841J and TFA9843BJ, facilitating modular design approaches in consumer electronics. The device utilizes a DBS9P plastic DIL-bent-SIL power package with an exposed die pad for efficient heat dissipation.

Replacement Considerations

Pin-compatible substitutes include TFA9841J, TFA9842J, TFA9843J, and TFA9843BJ. Verify functional equivalence regarding gain and protection thresholds before substitution.

FAQ

How does the TFA9842BJ handle thermal protection?

It uses multiple internal temperature sensors to detect local power stage temperatures around 185 °C and global chip temperatures around 150 °C, automatically switching off the power stages temporarily to prevent damage.

What is the input configuration cutoff frequency?

With standard external components (Ri = 60 kΩ and Ci = 220 nF), the input cutoff frequency is approximately 12 Hz.