LM4891ITP/NOPB

Audio Amplifiers Overview

The LM4891ITP/NOPB is a Boomer® series audio power amplifier designed for mobile phones and portable communication devices. It delivers 1W continuous average power to an 8Ω BTL load with less than 1% THD+N from a 5VDC supply, or 400mW at 3.3V. Operating on a single supply voltage ranging from 2.2V to 5.5V, it features ultra-low current shutdown mode (0.1µA typical), thermal shutdown protection, and advanced pop & click circuitry. The device requires no output coupling capacitors, snubber networks, or bootstrap capacitors.

Audio Amplifiers Feature Summary

• Ultra-low current shutdown mode minimizes power consumption in idle states.
• Advanced pop and click circuitry eliminates noises during turn-on and turn-off transitions.
• Bridge-tied load (BTL) output configuration allows driving capacitive loads without external coupling components.

Audio Amplifiers Applications

• Mobile Phones
• PDAs
• Portable Electronic Devices

Audio Amplifiers Procurement Notes

Verify the obsolete status of this component before procurement. Confirm that the ITP suffix corresponds to the specific package variant required for your design, as datasheet documentation covers multiple package options including Micro SMD, VSSOP, SOIC, and WSON. Ensure compatibility with existing PCB footprints and thermal management strategies given the device's age.

Audio Amplifiers Selection Notes

Select this component for low-voltage applications requiring high efficiency and minimal external parts count. Consider the trade-off between quiescent current and power output when operating below 5V. Verify that the system gain settings do not compromise the Power Supply Rejection Ratio (PSRR). Evaluate thermal dissipation requirements based on the chosen package type and copper heatsink area.

Audio Amplifiers Part Context

The LM4891 belongs to Texas Instruments' Boomer® Audio Power Amplifier Series. It is engineered specifically for portable electronics where minimal power consumption and small form factors are critical. The device integrates two operational amplifiers internally to facilitate bridge-tied load configurations, eliminating the need for large output capacitors typically found in single-ended designs.

Audio Amplifiers Replacement Considerations

LM4891MM/NOPB

Audio Amplifiers FAQ

How does the LM4891 eliminate turn-on and turn-off noises?

The device incorporates advanced pop and click circuitry that manages the ramp-up and ramp-down of the output voltages to prevent audible transients during state changes.

What is the function of the shutdown pin?

Driving the shutdown pin with a logic high signal turns off the amplifier's bias circuitry, reducing the supply current draw to a minimum of 0.1µA typical.