TPA321D - 700mW Mono Class-AB Audio Amp | TI
部品番号: TPA321D ✗ 生産終了| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $1.8757 | $1.88 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
TPA321D 概要
An audio power amplifier is an integrated circuit that increases the voltage and current capability of an analog audio signal so it can drive a loudspeaker or other finite impedance. A Class-AB amplifier provides linear operation with lower crossover distortion than a traditional Class-B design. A differential input accepts signal voltage between two input terminals, while a bridge-tied-load output uses both amplifier outputs to develop voltage across the speaker without requiring a speaker-coupling capacitor.
The TPA321 family is specified for 3.3 V and 5 V operation and supports a 2.5 V to 5.5 V supply range. At a 3.3 V supply, the manufacturer material states that the device can deliver 250 mW continuously into an 8-ohm bridge-tied load with less than 1% THD+N over the voice band. The TPA321D ordering option is supplied in the 8-pin SOIC package and supports a -40°C to +85°C operating-temperature range.
Differential input architecture can help reject common-mode noise when the source is balanced or when noise appears equally on both input conductors. The bridge-tied-load topology places the speaker between OUT+ and OUT-, so neither output pin should be grounded merely to establish a common reference. Input, supply, and output stability components must be implemented according to the manufacturer datasheet to preserve stable operation and acceptable distortion.
Typical uses include portable-device speakers, compact audio accessories, personal-audio products, and other low-voltage mono sound systems. The design is appropriate when a small internal speaker must be driven directly and board area is limited. At higher power or with a longer speaker connection, cable losses and load tolerance should be checked before release.
Decoupling capacitors should be placed close to the supply pins, and input components should be arranged to minimize the audio trace area. Thermal performance depends on supply voltage, output power, speaker impedance, PCB copper, and ambient temperature. This page combines verified product information with purchasing guidance and design context.
This data page distinguishes TPA321D from the broader TPA321 family, summarizes the electrically relevant evidence, and organizes sourcing and replacement questions. Values not explicitly supplied by the retrieved manufacturer or distributor data remain marked for verification rather than inferred.
ドロップイン代替品: TPA321D — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: TPA321D （同一形状・フットプリント） — 相違点: Package, Product Type, Operating Temperature, Output Configuration, Protection Features.
クイック比較ツール — 並列比較する代替部品を選択:
TPA321DR
✅ ドロップイン✓ 在庫あり
価格はお問い合わせください
データシートを見る →TPA321DG4
✅ ドロップイン📋 参考代替品（カタログ未掲載）
TPA321DRG4
✅ ドロップイン📋 参考代替品（カタログ未掲載）
TPA301D
✅ ドロップイン✓ 在庫あり
$0.35 / 個
データシートを見る →TPA321D 最大定格＆電気的特性
| Product Type | Mono Class-AB audio power amplifier |
| Rated Output Power | 700 mW |
| Power at 3.3 V into 8 Ohms | 250 mW continuous at less than 1% THD+N |
| Supply Voltage Range | 2.5 V to 5.5 V |
| Specified Supply Operation | 3.3 V and 5 V |
| 出力構成 | Bridge-tied load (BTL) |
| Input Architecture | Differential analog input |
| Channel Count | 1 channel |
| Amplifier Class | Class AB |
| パッケージ | 8-pin SOIC |
| 実装タイプ | Surface mount |
| 動作温度範囲 | -40°C to +85°C |
| Output Distortion | Less than 1% THD+N at 250 mW into 8 Ohms at 3.3 V |
TPA321D 8-pin soic ピン配置ガイド
TPA321D (8-pin soic パッケージ) のピン配置。 このアナログコンポーネントは、入力、出力、および電源ピンを備えています。オフセットナル、補償、イネーブルピンの設定については、メーカーのデータシートを参照してください。信号調整やアンプ回路に最適です。
詳細なピン配置データはありません: TPA321D.
詳細は データシート をご参照ください。
主な用途
TPA321D の用途: 6 件s: Portable-Device Speaker, 5 V Audio Accessory, Personal-Audio Product, Industrial Audible Alarm, Embedded Control-Board Annunciator, Low-Voltage Audio Test Fixture.
Portable-Device Speaker
The TPA321D suits a compact mono speaker stage powered from a 3.3 V system because the verified manufacturer material specifies 250 mW continuous output into an 8-ohm BTL load at less than 1% THD+N. Place the device beside the speaker connector, connect the loudspeaker between OUT+ and OUT-, and place supply bypass capacitors close to the IC. Differential input wiring helps reject common-mode noise when the source supports it. This design is most appropriate for small internal speakers where low supply voltage, limited board area, and direct BTL drive are priorities. Confirm thermal rise and cable loss because the stated output point does not guarantee unrestricted power into every impedance.
おすすめ
5 V Audio Accessory
The TPA321D is appropriate for a 5 V mono audio accessory because the manufacturer specifies 3.3 V and 5 V operation and identifies the amplifier as a 700 mW-class device. Its Class-AB BTL topology drives the load differentially, reducing the need for a traditional output coupling capacitor while keeping the signal path compact. Place local decoupling between the supply pins and ground, route OUT+ and OUT- as a short differential pair to the speaker, and verify the chosen speaker impedance. Compared with a higher-efficiency switching amplifier, the linear Class-AB architecture is straightforward but can dissipate more heat; the PCB copper area and enclosure ventilation therefore remain important at sustained high output.
おすすめ
Personal-Audio Product
The TPA321D can serve as the final mono amplification stage in a personal-audio product with an internal speaker and analog source. Differential inputs support balanced source connections or common-mode rejection, while the 2.5 V to 5.5 V supply range accommodates low-voltage portable rails. Use short ground returns, place input filtering close to the amplifier, and terminate the unused input exactly as directed by the manufacturer datasheet. The verified 250 mW result into 8 ohms at 3.3 V provides a concrete sizing point below the device's broader 700 mW class description. For voice prompts, music, or alert sounds, evaluate the actual load impedance and frequency response rather than relying only on headline power.
おすすめ
Industrial Audible Alarm
The TPA321D can amplify a low-level alarm or annunciator signal in a compact industrial control product operating from a 3.3 V or 5 V rail. Its BTL output drives a small speaker without connecting either output to ground, and the specified 250 mW continuous capability into 8 ohms at 3.3 V is suitable for moderate audible levels. Place the amplifier close to the speaker connector to limit EMI and cable loss, while keeping analog input routing away from switching nodes and power inductors. Validate alert intelligibility, distortion, startup behavior, and enclosure acoustics in the final system. If battery life dominates and the speaker is rarely active, a standby control or more efficient class-D solution may be preferable.
おすすめ
Embedded Control-Board Annunciator
The TPA321D is a practical choice for a low-voltage embedded controller that must drive an onboard piezo speaker or small dynamic annunciator. The verified 3.3 V operating point delivers 250 mW continuously into an 8-ohm BTL load below 1% THD+N, giving designers a repeatable baseline for acoustic testing. Differential inputs can receive a buffered waveform from a DAC or digital-to-analog conversion stage, and the SOIC-8 package supports conventional surface-mount assembly. Confirm that the actual speaker presents a safe load across frequency and temperature. Keep the speaker return isolated from sensitive analog grounds where practical, and use the manufacturer's input and bypass recommendations to prevent oscillation or unintended noise injection into adjacent control circuitry.
おすすめ
Low-Voltage Audio Test Fixture
The TPA321D can serve as the speaker driver in a compact audio test fixture built around a low-voltage USB or embedded supply. Its defined 3.3 V and 5 V operation permits repeatable characterization without a high-voltage amplifier supply, while the BTL topology requires the fixture speaker to float between OUT+ and OUT-. Provide local supply bypassing, use short speaker leads, and expose separate input and ground test points for debugging. The verified 250 mW continuous point into 8 ohms at 3.3 V is useful for defining a safe starting test level. Before applying continuous audio, verify the load, output waveform, temperature rise, and distortion so a fixture experiment does not overdrive the amplifier or the connected speaker.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: TPA321D — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | TPA321DR | TPA321DG4 | TPA321DRG4 | TPA301D |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
主な差別化要因
- Verified low-voltage mono audio specification （vs TPA301D)
- Differential-input BTL architecture （vs TPA301D)
- Same-family ordering flexibility （vs TPA301D)
設計ノート
Place the manufacturer-required bypass capacitors directly beside the supply and ground pins, keeping their loops short. Route differential inputs away from switching nodes, inductors, and speaker-return paths. The verified BTL architecture requires the speaker between OUT+ and OUT-; grounding either output can short the bridge and damage the device.
Keep OUT+ and OUT- traces short, closely coupled, and away from sensitive microphone or sensor inputs. Use a compact ground reference beneath the amplifier where supported by the manufacturer layout guidance. Because the target supports 3.3 V and 5 V operation, verify the actual supply range, output impedance, and distortion rather than extrapolating from the 250 mW test point.
Do not treat a same-package listing as proof of drop-in compatibility. TPA301D appears in a comparison result as SOIC-8, but the supplied evidence does not establish pin mapping, BTL behavior, or electrical limits. For any substitution, compare pin functions, supply voltage, output topology, load range, shutdown behavior, and stability requirements against the manufacturer datasheets.
コンプライアンス情報
The supplied verified data does not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status for TPA321D.