TPA301D - 350mW Mono Class-AB Amplifier | Texas Instruments
MPN: TPA301D ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.75 | $0.75 |
| 10 | $0.5783 | $5.78 |
| 100 | $0.45 | $45.00 |
| 500 | $0.4 | $200.00 |
| 1,000 | $0.35 | $350.00 |
TPA301D Overview
An audio power amplifier is an integrated circuit that converts a low-level analog audio signal into sufficient current and voltage to drive a loudspeaker or other audio load. A mono Class-AB amplifier uses one signal channel, while the TPA301D BTL architecture places the load between two output nodes rather than connecting one output to ground. This arrangement can improve speaker drive efficiency while requiring correct differential output routing and suitable input/output decoupling.
The principal verified features are 350 mW class output capability, 3.3 V and 5 V supply compatibility, an 8-pin SOIC package, low 0.15 uA shutdown quiescent current, and integrated thermal and short-circuit protection. The TPA301 family also offers a surface-mount PowerPAD MSOP option according to the TI product page, although the TPA301D orderable variant is identified as 8-SOIC by distributor data. The manufacturer explicitly states that no special bypassing, gain-setting, or stability adjustments are required merely because the supply is 3.3 V rather than 5 V; output power is the important operating consideration.
Because the part is designed around low-voltage BTL audio drive, circuit layout should preserve the differential output topology and place required capacitors close to the device pins. The input and output networks should be checked against the manufacturer datasheet for the selected supply, gain, load, and operating mode. The device should not be selected solely by its nominal 350 mW label: continuous speaker power, distortion, thermal conditions, supply headroom, and available PCB area determine practical performance.
Typical applications include portable voice boxes, compact speakers, personal-audio accessories, embedded audio modules, and low-voltage consumer products. In a 3.3 V system, the verified 250 mW into 8 ohms condition provides a useful baseline, while 5 V operation provides additional output capability. For applications requiring more power, a different amplifier class or package should be evaluated rather than assuming that a higher supply alone preserves the same thermal and distortion performance.
A practical design tip is to validate the speaker impedance and wiring before layout approval. A BTL amplifier must never be configured like a single-ended amplifier with one output grounded. Review the TI datasheet for recommended input, bypass, feedback, output, and decoupling networks, then test worst-case low-supply, high-temperature, maximum-volume conditions.
This page combines verified manufacturer and distributor information with practical selection guidance, datasheet-oriented FAQs, and engineering-oriented design notes. It is intended to help engineers identify whether the TPA301D fits a low-voltage mono-speaker design before committing to a PCB footprint or supply architecture.
Drop-in alternatives for TPA301D — 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 TPA301D (same form factor and footprint) — differing in Product Type, Rated Output Power, Output Configuration, Output Topology, Protection Features.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TPA301DR
✅ Drop-In✓ In Stock
$0.74 / Unit
View Datasheet →TPA301D
✅ Drop-In✓ In Stock
$0.35 / Unit
View Datasheet →TPA311D
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →LM386
✅ Drop-In📋 Reference alternative (not in catalog)
TPA321D
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →TPA301D Maximum Ratings & Electrical Characteristics
| Product Type | Mono Class-AB audio power amplifier |
| Rated Output Power | 350 mW |
| Verified 3.3 V Output Power | 250 mW continuous into 8 ohm BTL at less than 1% THD+N throughout the voice band |
| Supply Voltage Operation | 3.3 V and 5 V |
| Output Topology | Bridge-tied load (BTL) |
| Audio Channel Count | 1 channel, mono |
| Package | 8-pin SOIC |
| Mounting Type | Surface mount |
| Shutdown Quiescent Current | 0.15 uA |
| Protection Features | Thermal and short-circuit protection |
| Operating Temperature | -40 C to +85 C |
| RoHS Status | Compliant |
| Lifecycle Status | Active |
| Manufacturer Product Page | TPA301 |
| Manufacturer Data Sheet Revision | Rev. E |
| Distributor Package Description | 8-SOIC |
| Distributor Price Reference | $0.5783 at MOQ 10, as of 2026-10-23 |
TPA301D 8-soic Pin Configuration Guide
Pin configuration for TPA301D (8-soic 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 TPA301D.
Refer to the datasheet for full pin configuration.
Typical Applications
TPA301D is suitable for 6 applications: Portable Voice Speaker, Embedded Audio Module, Low-Voltage Consumer Accessory, Personal Audio Device, Industrial Audible Alarm, Compact Learning or Notification Device.
Portable Voice Speaker
The TPA301D fits portable voice products that use one internal speaker and a low-voltage battery or regulated rail. Its mono Class-AB architecture and BTL output avoid wasting output capability on a grounded speaker connection, while the verified 3.3 V specification supports system partitioning around common low-voltage logic rails. The verified 250 mW into 8 ohms condition gives a concrete baseline for voice playback, although enclosure limits, battery droop, and thermal conditions determine usable volume. Designers should follow the TI recommended bypass and output network, validate the speaker wiring, and test distortion at maximum signal level before finalizing the enclosure.
Recommended
Embedded Audio Module
The TPA301D is appropriate for compact embedded audio modules that operate from 3.3 V or 5 V and need a local speaker output rather than a line-level signal. The 8-pin SOIC package supports conventional surface-mount assembly, while the manufacturer states that 3.3 V and 5 V operation have no special bypassing, gain-setting, or stability considerations. In an embedded design, the amplifier should be placed close to the speaker connector and decoupling network, with differential BTL routing kept short and away from sensitive analog or digital traces. Validate the host audio amplitude, shutdown polarity, and maximum continuous output under the module’s temperature range.
Recommended
Low-Voltage Consumer Accessory
The TPA301D can serve low-voltage consumer accessories that announce status, play prompts, or reproduce short audio clips through one small speaker. The 350 mW class designation and 3.3 V compatibility make it relevant to compact products where a larger Class-D or high-power amplifier would be unnecessary. The BTL topology requires a speaker connected between the two output nodes; grounding either output can damage the device or invalidate the test result. Use the TI application guidance to select gain and bypassing, then check acoustic output at minimum battery voltage because speaker power can fall as the supply rail declines.
Recommended
Personal Audio Device
The TPA301D is suitable for small personal-audio products that need one internal transducer and prioritize low supply voltage and compact implementation over multi-channel output. The manufacturer specifies operation at 3.3 V and 5 V and reports an 8-SOIC option for the TPA301D, making it convenient for conventional PCB assembly. Designers should budget for speaker impedance, peak audio level, and thermal rise because nominal wattage does not define perceived loudness. The 0.15 uA shutdown current can help battery life when playback is inactive, provided the control polarity and timing are verified from the datasheet.
Recommended
Industrial Audible Alarm
The TPA301D can be used in a compact industrial audible-alarm module when the required sound level fits the verified low-voltage output capability. The 3.3 V and 5 V supply options help align the amplifier with industrial controller rails, while thermal and short-circuit protection provide useful fault-management features. The design must still include appropriate input attenuation or limiting so that alarm tones do not exceed the amplifier’s distortion and thermal limits. Place the speaker output and BTL return path away from precision sensing circuits, and verify the enclosure’s acoustic response across temperature and supply tolerance.
Recommended
Compact Learning or Notification Device
The TPA301D supports compact educational toys, notification modules, and appliance feedback devices that reproduce a single audio channel from a low-voltage controller. A mono BTL amplifier reduces the need for a stereo output path and can simplify speaker connection when the enclosure provides only one transducer. The verified 8-SOIC package and 350 mW class output make the device appropriate for a small, conventional surface-mount design, but the final acoustic output must be measured with the actual speaker and enclosure. Include local decoupling and controlled gain to avoid distortion during sustained tones.
Recommended
Recommended Products Summary
Engineering reference data for TPA301D — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TPA301DR | TPA301D | TPA311D | LM386 | TPA321D |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC |
| Product Type | Mono Class-AB audio power amplifier | TPA301-family mono BTL amplifier | Mono Class-AB BTL amplifier | Mono audio amplifier | Audio power amplifier | Approximately 700 mW mono Class-AB amplifier |
Key Differentiators
- Low-voltage mono BTL output (vs TPA321D)
- Very low shutdown quiescent current (vs TPA301DR)
- Integrated fault protection (vs LM386)
Design Notes
Treat the BTL output as a differential load. Do not connect either output node to system ground, and do not add a speaker return to ground unless the exact TI application circuit specifies it. Place the input, bypass, and feedback components close to their associated pins, and route the two output conductors as a compact differential pair to the speaker connector. This prevents the output stage from behaving like a single-ended amplifier and reduces radiated noise pickup.
The verified 3.3 V specification of 250 mW into 8 ohms at less than 1% THD+N is a useful design baseline, not a guarantee for every temperature, enclosure, or supply condition. Validate sustained full-scale audio at minimum supply voltage and maximum ambient temperature. If the amplifier is mounted in a sealed enclosure, provide copper around the SOIC pins and verify that the speaker load cannot present a lower impedance than the tested design.
Do not infer pin compatibility from an 8-SOIC package alone. The provided data identifies TPA301D as 8-SOIC and mentions TPA301D, TPA311D, LM386, and TPA321D as comparison candidates, but it does not include complete verified pin-assignment tables for every candidate. Before substitution, compare pin numbers, gain-setting components, bypass requirements, output polarity, shutdown logic, supply limits, and output impedance.
Compliance Information
The verified component listing states RoHS Compliant. The supplied data does not verify REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification status for TPA301D.