LM4891MM/NOPB

Audio Amplifiers Overview

The LM4891MM/NOPB is a 1-watt audio power amplifier from the Boomer series, designed for mobile phones and portable devices. It delivers continuous average power to an 8-ohm BTL load with less than 1% distortion (THD+N) from a 5VDC supply. The device operates on a 2.2V to 5.5V supply, features ultra-low current shutdown mode, and includes thermal shutdown protection. It eliminates pop and click noises during transitions and requires no output coupling capacitors or bootstrap networks.

Audio Amplifiers Feature Summary

• Bridge-tied load (BTL) configuration capable of driving capacitive loads without external snubber networks.
• Advanced circuitry eliminates audible noises during turn-on and turn-off transitions.
• Unity-gain stable architecture allowing flexible external gain configuration via resistors.
• Integrated thermal shutdown mechanism protects the device under excessive heat conditions.

Audio Amplifiers Applications

• Mobile phones
• Personal Digital Assistants (PDAs)
• Portable electronic devices

Audio Amplifiers Procurement Notes

Verify component authenticity through authorized Texas Instruments distributors or direct channels. Confirm the specific package variant matches design requirements, as the LM4891 family utilizes multiple form factors including MicroSMD, VSSOP, SOIC, and WSON. Ensure the ordering suffix corresponds to the desired physical footprint and termination style before finalizing procurement orders.

Audio Amplifiers Selection Notes

Select this amplifier for low-voltage applications requiring high efficiency and minimal external components. The device supports differential drive to double output swing compared to single-ended configurations. Designers must account for power dissipation limits and ensure adequate PCB copper area for thermal management when operating near maximum ratings.

Audio Amplifiers Part Context

This component belongs to the Texas Instruments Boomer audio power amplifier series. These amplifiers are engineered to provide high-quality output power while minimizing the number of required external components. The LM4891 specifically targets portable communication devices where space constraints and low power consumption are critical design parameters.

Audio Amplifiers Replacement Considerations

LM4890MM/NOPB

Audio Amplifiers FAQ

Does the LM4891 require output coupling capacitors?

No, the LM4891 does not require output coupling capacitors, snubber networks, or bootstrap capacitors due to its bridge-tied load architecture.

How is the shutdown function activated?

The shutdown mode is activated by driving the shutdown pin with a logic high voltage, which minimizes supply current draw in idle mode.