TPA311DG4

Overview

The TPA311DG4 is a mono audio power amplifier from Texas Instruments, manufactured in an 8-pin SOIC (D) package. It operates on a single supply voltage ranging from 2.5 V to 5.5 V. The device supports both bridge-tied load (BTL) and single-ended (SE) output configurations. In BTL mode with an 8-ohm load, it delivers up to 350 mW at 5 V and 250 mW at 3.3 V. Key electrical characteristics include a unity-gain bandwidth of 1.4 MHz, a shutdown current of 7 µA at 3.3 V, and total harmonic distortion plus noise of 1.3% at 250 mW output.

Feature Summary

• Supports dynamic switching between bridge-tied load and single-ended modes for flexible speaker and earphone driving.
• Includes integrated depop circuitry to minimize audible noise during power cycling and shutdown transitions.
• Features built-in thermal overload and short-circuit protection to ensure operational reliability under fault conditions.

Applications

• Low-voltage portable electronic devices requiring internal speaker amplification
• Cellular communication equipment optimized for voice band frequencies
• Battery-powered systems utilizing external earphones via single-ended configuration

Procurement Notes

Verify the specific 'G4' suffix indicates lead-free compliance and RoHS status as per Texas Instruments standards. Confirm the SOIC-8 package dimensions match your PCB footprint requirements. Ensure the design accounts for the thermal dissipation limits specified in the datasheet for the D package variant under expected operating temperatures.

Selection Notes

Select this component when designing low-voltage audio circuits that require high efficiency without external coupling capacitors. The BTL configuration is ideal for maximizing output power into low-impedance loads like 8-ohm speakers. Consider the SE mode if driving high-impedance headphones or if space constraints prohibit the differential output layout required for bridge-tied operation.

Part Context

The TPA311DG4 belongs to the TPA311 family of Class-AB audio amplifiers designed specifically for battery-operated applications. It serves as a compact solution for replacing larger discrete amplifier designs or other ICs requiring bulky output capacitors. The device integrates bias control and input coupling networks to simplify schematic design while maintaining audio fidelity within the voice band.

Replacement Considerations

TPA311D: Identical functional specifications but may differ in packaging or environmental compliance details.

FAQ

How does the TPA311DG4 eliminate the need for output coupling capacitors?

In bridge-tied load (BTL) mode, the amplifier drives both ends of the load differentially. This configuration cancels DC offsets, allowing direct connection to the speaker without blocking capacitors.

What is the purpose of the SE/BTL pin?

The SE/BTL pin allows the user to switch the amplifier between single-ended and bridge-tied load modes. Holding it low enables BTL mode, while holding it high enables SE mode.