BD3861FS - 3-Band Audio Equalizer Sound Processor | ROHM
料号： BD3861FS ⚠ 最后一次采购BD3861FS 概述
An audio sound processor is a specialized analog signal-chain IC that adds source selection, tone shaping, and level control functions before a power amplifier. The BD3861FS combines those functions into one IC, allowing a compact consumer-audio design to implement bass, midrange, and treble adjustment without requiring a separate network of analog switches and passive tone-control circuitry.
According to the ROHM product page, the key feature is the integrated three-band equalizer. The manufacturer documentation describes high signal-to-noise performance obtained through a two-stage architecture, while the two-wire serial control provides electronic adjustment from a remote-control processor or system controller. The verified sources also identify the family as supporting sound-quality designs that incorporate source selectors and serve as the preamplifier immediately ahead of a power amplifier.
Typical applications include boom-box and portable-stereo signal paths, compact micro-audio systems, and preamplifier stages that feed an external audio power amplifier. Its integration can reduce external switching components and simplify control firmware, although the 32-pin SSOP footprint is larger than modern compact audio-controller packages. System designers should confirm the complete pin functions, electrical limits, and serial-command table in the manufacturer datasheet before laying out a new board.
Because the BD3861FS is in Last Time Buy status, engineers should avoid new-volume designs unless the supply situation is commercially acceptable and a documented time-buffer plan exists. For an active production program, evaluate a currently supported audio processor with the same required control protocol, source-selection functions, equalizer bands, and system-level pin compatibility instead of assuming that a mechanically similar IC is electrically interchangeable.
This page consolidates the verified manufacturer and distributor information, identifies the product's discontinuation status, and separates confirmed capabilities from electrical details that must be confirmed in the original datasheet. Pricing, stock, and remaining-life conditions are quote-dependent and are not presented as guaranteed availability.
直接替换替代料： BD3861FS ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
BD3861FS-E2
✅ 直接替换📋 参考替代料（不在目录中）
BD3403FV
✅ 直接替换📋 参考替代料（不在目录中）
BD3883FS
✅ 直接替换📋 参考替代料（不在目录中）
BD3861FS 最大额定值与电气特性
| Product Type | Analog sound processor |
| Equalizer Configuration | Built-in 3-band equalizer |
| Control Interface | 2-wire serial interface |
| Architecture | 2-stage signal architecture |
| Signal-to-Noise Performance | High S/N, per manufacturer description |
| Number of Equalizer Bands | 3 bands |
| 封装 | 32-pin SSOP (PDSO32) |
| 安装类型 | Surface Mount |
| Product Category | Audio sound controller / sound processor |
| 生命周期状态 | Last Time Buy |
| Discontinuation Status | Product discontinuation (EOL) announced |
| RoHS Compliance | RoHS compliant |
BD3861FS 32-pin ssop (pdso32) 引脚配置指南
BD3861FS（32-pin ssop (pdso32) 封装）的引脚配置。 该模拟元件具有输入、输出和电源引脚。请参阅制造商数据手册以了解失调调零、补偿和使能引脚配置。适用于信号调理和放大器电路。
暂无详细引脚数据： BD3861FS.
请参阅 数据手册 以查看完整引脚配置。
典型应用
BD3861FS 适用于 6 应用s: Boom-Box Audio Signal Path, Mini-Audio System Preamplifier, Micro-Audio Equalization Stage, Front-Stage Tone Control for Power Amplifier, Remote-Controlled Source Selector, Legacy Audio Product Repair and Replenishment.
Boom-Box Audio Signal Path
The BD3861FS fits boom-box designs because it combines source selection with a built-in three-band equalizer ahead of the power amplifier. Its two-wire serial control allows bass, midrange, and treble settings to be adjusted electronically from the main controller, reducing the need for a dedicated mechanical tone-control network. The manufacturer's high-S/N two-stage architecture supports the stated sound-quality use case. Because exact gain limits and signal-level limits are not present in the verified snippets, engineers should reproduce the ROHM reference signal levels and speaker-amplifier input conditions before production. The 32-pin SSOP footprint is larger than contemporary compact controllers, so reserve adequate routing space for analog inputs, control lines, and decoupling.
推荐
Mini-Audio System Preamplifier
The BD3861FS is suitable for the front-stage preamplifier function in a mini-audio system, where multiple sources feed an external power amplifier through tone control. Its integrated three-band equalizer allows one analog IC to control the tonal balance of selected sources instead of distributing separate bass and treble networks. The verified two-wire serial interface is useful when the system already has a remote-control MCU, although the specific command map must be implemented from the manufacturer documentation. Confirm the source-selection architecture, grounding strategy, and maximum signal levels against the datasheet. As a Last Time Buy part, this role is most appropriate for an existing product undergoing controlled repair or replenishment.
推荐
Micro-Audio Equalization Stage
In a micro-audio product, the BD3861FS provides a consolidated tone-shaping block with three adjustable bands and electronic control over a two-wire serial bus. This can be helpful where enclosure space limits the number of external rotary controls and where the controller must present presets such as flat, bass boost, or speech. The manufacturer's two-stage implementation and high signal-to-noise claim make the IC relevant to compact audio quality designs, but the verified data does not state the exact center frequencies or boost attenuation. Validate those values, along with headroom at maximum gain, before choosing filter or capacitor values. Existing designs should also preserve the correct firmware command sequence during maintenance.
推荐
Front-Stage Tone Control for Power Amplifier
The BD3861FS can serve as the front-stage sound controller between a source selector and a power amplifier, providing a three-band equalizer without a large collection of discrete tone networks. The verified manufacturer material specifically describes front-stage preamplifier use, making it a natural fit for legacy hi-fi and mini-component designs. Its high-S/N two-stage architecture supports low-noise audio processing, while two-wire serial control provides remote adjustment. Verify the IC's exact input sensitivity, output level, and recommended source impedance because these values were not recoverable from the supplied snippets. During repair, compare the replacement device against the original board's ground reference and decoupling layout to avoid audible hum or level mismatch.
推荐
Remote-Controlled Source Selector
The BD3861FS is applicable when a compact audio system needs electronically selected sources and adjustable tone controls rather than a purely mechanical selector. Its two-wire serial interface reduces the number of direct MCU-to-audio I/O lines and lets the system controller apply presets. The integrated equalizer can then maintain a consistent sound character between radio, tape, or auxiliary inputs, subject to the manufacturer's recommended gain structure. Because the verified snippets do not enumerate the available input paths or command registers, firmware and schematic designers must obtain the complete control tables from the manufacturer PDF. For legacy product repair, use the original command timing and pin assignment rather than assuming compatibility with unrelated two-wire audio codecs.
推荐
Legacy Audio Product Repair and Replenishment
The BD3861FS is primarily relevant to repair, refurbishment, and controlled replenishment of products that already use this sound processor. Because ROHM has announced discontinuation and identifies the device as Last Time Buy, securing verified stock can be more important than comparing the newest audio features. Before ordering, inspect the manufacturer marking, confirm the 32-pin SSOP footprint, and compare the exact ordering code. The available -E2 designation should be checked with ROHM rather than automatically substituted. For long-term maintenance, request lot-level traceability, date-code information, a test report, and written remaining-life information. This approach reduces the risk that a mechanically similar sound processor is fitted but does not reproduce the original control behavior.
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推荐产品汇总
工程参考数据： BD3861FS ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | BD3861FS-E2 | BD3403FV | BD3883FS |
|---|---|---|---|---|
| Package | SSOP-32 (PDSO32) | SSOP-32 (PDSO32) - same | SSOP-32 (PDSO32) - same | SSOP-32 (PDSO32) - same |
| Brand | ROHM Semiconductor | ROHM Semiconductor | ROHM Semiconductor | ROHM Semiconductor |
| Product Type | Analog sound processor with 3-band equalizer | Related sound-processor ordering designation | ROHM sound processor with 3-band equalizer | ROHM sound processor with 3-band equalizer |
| Equalizer Bands | 3 bands | 3 bands | 3 bands | 3 bands |
| Control Interface | 2-wire serial interface | 2-wire serial interface | 2-wire serial interface | 2-wire serial interface |
关键差异点
- Purpose-built three-band analog equalizer in one sound-processor IC （对比 BD3403FV)
- Direct family ordering relationship with the original device （对比 BD3883FS)
- Two-wire serial control for compact source and tone management （对比 BD3861FS-E2)
设计说明
Do not treat the BD3861FS-E2 suffix as permission to substitute without verification. The supplied comparison result associates both devices with the same 32-pin tone-control format but explicitly warns that similar function does not guarantee identical circuit structure or parameters. Confirm the manufacturer ordering table, exact pin assignments, serial-command timing, and lifecycle status before replacing the original device. For new designs, verify that the candidate's control protocol is implemented by the existing system firmware rather than merely sharing the same package count.
Preserve the original board's analog grounding, input-routing, and decoupling layout when repairing a product that uses the BD3861FS. The device performs low-level audio selection and tone shaping, so long analog traces and shared high-current return paths can increase hum or reduce the signal-to-noise performance claimed by the manufacturer. Place supply-bypass capacitors close to the IC and keep the sound-path routing short. Because the exact pin functions and recommended layout were not included in the supplied snippets, use the ROHM datasheet and application example as the controlling references.
The verified data does not state the BD3861FS supply-voltage range or absolute maximum ratings, so neither value may be inferred from typical audio-system rails. Before energizing a repair board, confirm the original schematic, the fitted regulator, and the manufacturer limits for the exact ordering code. Treat the Last Time Buy status as a supply-planning constraint: obtain lot traceability and a written supplier commitment rather than relying on a distributor search result alone.
合规信息
The verified comparison result identifies the BD3861FS as RoHS compliant. No verified REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations were supplied, so those fields remain unknown. The product is an analog audio IC rather than an automotive-qualified device.
