TPA311DR - 350mW Mono Class-AB Amplifier | Texas Instruments
MPN: TPA311DR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.95 | $0.95 |
| 10 | $0.82 | $8.20 |
| 100 | $0.64 | $64.00 |
| 500 | $0.51 | $255.00 |
| 1,000 | $0.43 | $430.00 |
| 3,000 | $0.37 | $1,110.00 |
TPA311DR Overview
An audio power amplifier is an integrated circuit that converts a low-level audio input into a higher-current signal capable of driving a loudspeaker or other transducer. The TPA311 belongs to the Class-AB amplifier hierarchy within audio amplifiers and power-management ICs. Its bridge-tied-load mode increases usable output voltage into a differential speaker, while single-ended mode allows the same device to drive an external earphone when the system requires a grounded output.
Key features include 350 mW rated output capability, compatibility with 3.3 V and 5 V supplies, integrated BTL-to-SE mode control, integrated depop circuitry, and built-in thermal and short-circuit protection. These features make the device suitable for portable audio, voice terminals, personal-audio products, and other compact systems in which a single-speaker or earphone output is needed without a large external amplifier module.
The architecture is optimized for low-voltage operation. At a 3.3 V supply, the manufacturer documentation describes 250 mW continuous output into an 8-ohm BTL load at less than 1% THD+N across voice-band frequencies. The lower output-power figure reflects the device's 3.3 V operating condition; the family-level headline rating is 350 mW. BTL operation suppresses the DC output offset at the speaker and can provide greater output swing than a conventional single-ended amplifier.
Typical applications include portable media players, personal audio accessories, voice-call terminals, compact speakers, and low-voltage embedded audio products. The TPA311DR can be selected when the board uses an 8-pin SOIC footprint and requires integrated protection rather than a discrete output stage.
A key design consideration is output-mode configuration: the mode-control function must be connected or configured as required by the manufacturer reference design for the intended BTL or SE load. Input and output decoupling, speaker-return routing, thermal copper, and clean grounding are essential for low distortion and stable operation.
This page consolidates verified manufacturer and distributor information, drop-in candidate screening, application guidance, and practical PCB considerations. It also distinguishes explicitly sourced facts from unavailable specifications, helping engineers make a defensible design decision without relying on a generic distributor listing alone.
Drop-in alternatives for TPA311DR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with TPA311DR (same form factor and footprint).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesTPA311DR Maximum Ratings & Electrical Characteristics
| Product Type | Mono Class-AB audio power amplifier |
| Output Power | 350 mW |
| 3.3 V Continuous Output into 8 ohm BTL | 250 mW at less than 1% THD+N |
| Supply Compatibility | 3.3 V and 5 V operation |
| Output Configuration | Bridge-tied load (BTL) or single-ended (SE) |
| BTL-to-SE Mode Control | Integrated |
| Depop Circuitry | Integrated |
| Thermal Protection | Integrated |
| Short-Circuit Protection | Integrated |
| Channel Count | 1 channel |
| Package | 8-pin SOIC |
| Mounting Type | Surface mount |
| Ordering Package | Tape and reel |
TPA311DR tape and reel Pin Configuration Guide
Pin configuration for TPA311DR (tape and reel package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for TPA311DR.
Refer to the datasheet for full pin configuration.
Typical Applications
TPA311DR is suitable for 6 applications: Portable Voice Terminal, Personal Audio Accessory, Low-Voltage Embedded Speaker, Smart Home Audio Node, Industrial Voice Annunciator, Compact Communication Speakerphone.
Portable Voice Terminal
The TPA311DR fits compact voice terminals powered from a 3.3 V rail because the Texas Instruments TPA311 family is fully specified for 3.3 V and 5 V operation. At 3.3 V, the device can deliver 250 mW continuously into an 8-ohm BTL load at less than 1% THD+N across the voice band. Place the amplifier beside the speaker connector, return the BTL outputs directly to the speaker, and keep the traces short to reduce pickup. The integrated thermal and short-circuit protection supports portable equipment, while the integrated depop circuitry helps suppress startup transients.
Recommended
Personal Audio Accessory
TPA311DR is suitable for a compact personal-audio product using either a small differential speaker or an external earphone. Its bridge-tied-load mode supports a differential speaker connection, while the integrated BTL-to-SE mode control permits a grounded single-ended output when earphone operation is required. This flexibility can simplify one-amplifier product architectures. Designers must check the earphone impedance and output level against the complete datasheet limits, configure mode control for the selected load, and use the manufacturer's recommended input and output capacitors to preserve low distortion.
Recommended
Low-Voltage Embedded Speaker
The TPA311DR provides a practical output stage for low-voltage embedded products requiring a small onboard speaker rather than a high-power audio bus. Its 350 mW family rating and documented 250 mW continuous delivery into 8 ohms from 3.3 V at less than 1% THD+N make it appropriate for voice prompts, status messages, and simple media playback. Use BTL output to maximize voltage swing to a differential speaker, provide local supply bypassing, and maintain a low-impedance ground return. Confirm the speaker's minimum impedance and thermal rating before finalizing the load.
Recommended
Smart Home Audio Node
TPA311DR can provide local speaker amplification in a smart-home audio node that operates from a 3.3 V or 5 V supply. The single-channel Class-AB topology is suitable for one compact speaker, while BTL-to-SE mode control supports alternate speaker and earphone test configurations. Integrated depop, thermal, and short-circuit protection simplify protection planning. In a networked enclosure, keep the amplifier return current away from digital and radio grounds, use short speaker routes, and validate acoustic performance across temperature because Class-AB dissipation can increase with supply-to-output voltage difference.
Recommended
Industrial Voice Annunciator
TPA311DR is applicable to compact industrial voice annunciators where a low-voltage controller drives a small speaker. The 3.3 V compatibility and 250 mW continuous BTL output documented at less than 1% THD+N support intelligible voice-band playback, while integrated thermal and short-circuit protection adds resilience in unattended equipment. Industrial products should still enforce isolation between noisy motor or relay power and the audio path. Use a dedicated analog supply branch, low-impedance grounding, and a series output resistor or other network only where supported by the manufacturer's reference design.
Recommended
Compact Communication Speakerphone
The TPA311DR suits a compact communication speakerphone requiring one mono speaker output from a low-voltage system. A 3.3 V rail can support 250 mW continuous into an 8-ohm BTL load at less than 1% THD+N across the voice band, providing adequate headroom for spoken audio in small enclosures. Use BTL to reduce output offset at the speaker and preserve common-mode rejection, while ensuring both output nodes have symmetrical routing. The integrated protections are valuable for voice-call products, but thermal performance still depends on PCB copper and the selected supply and output levels.
Recommended
Recommended Products Summary
Engineering reference data for TPA311DR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TPA311DG4 | TPA311D | TPA701DR | TPA721DR |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-SOIC | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same |
| Channel Configuration | 1-channel mono | 1-channel mono | 1-channel mono | 1-channel mono | 1-channel mono |
| Amplifier Class | Class-AB | Class-AB | Class-AB | Class-AB | Class-AB |
| Headline Output Power | 350 mW | 350 mW | 350 mW | 700 mW class | 0.7 W class |
Key Differentiators
- Integrated BTL-to-SE mode control (vs TPA701DR)
- Defined low-voltage operating coverage (vs TPA721DR)
- Integrated transient and fault protection (vs TPA721DR)
Design Notes
Place the input capacitor, supply bypass capacitor, and output-network components directly beside their associated TPA311DR pins. Keep the two BTL speaker traces short, closely coupled, and free of test pads or unrelated high-current paths. In single-ended mode, separate the selected SE output from the unused output node exactly as shown in the Texas Instruments reference design. Symmetrical speaker routing reduces differential pickup and helps preserve low distortion.
Use the manufacturer's recommended supply and output capacitance values, including effective ceramic capacitance after DC-bias derating. Decouple the 3.3 V or 5 V amplifier rail locally with a low-inductance ceramic bypass capacitor and place a bulk capacitor near the power source. Do not route speaker-return current through the sensitive input ground. Validate startup and shutdown behavior with the integrated depop circuitry enabled, especially when the amplifier shares a rail with a load that produces large transients.
Estimated: Class-AB dissipation depends on the selected operating point, and no complete efficiency or thermal-resistance table was supplied for this page. At an illustrative 3.3 V supply and 250 mW output into 8 ohms in BTL mode, the device is approaching its stated continuous-power condition, so provide uninterrupted ground-plane copper under the SOIC and verify junction temperature in the final enclosure. Increase copper area or reduce output power when ambient temperature is high; the integrated thermal protection is not a substitute for adequate heat spreading.
Do not assume that every 8-SOIC mono amplifier is an electrical drop-in substitute. TPA311DR specifically provides integrated BTL-to-SE mode control, depop circuitry, thermal protection, and short-circuit protection. Before fitting TPA701DR, TPA721DR, or another cross-reference result, compare every pin, supply limit, gain setting, output mode, load impedance, stability behavior, and protection mechanism. A matching footprint prevents soldering problems but does not guarantee functional compatibility.
Compliance Information
The supplied verified data does not explicitly state compliance for the TPA311DR. No environmental or automotive qualification claims are inferred from the manufacturer family information.