BD37521FS-E2 2-Band Audio Processor | ROHM | Car Audio
N.º da peça: BD37521FS-E2 ✗ Fim de vidaBD37521FS-E2 Visão geral
An audio tone processor, also called a sound processor, sits between audio sources and the power-amplifier stage. It selects and conditions left- and right-channel signals before passing them onward. The BD37521FS-E2 belongs to the broader sound-processor and analog-audio-processing hierarchy, reducing the number of separate external gain, volume, selector, and equalizer blocks required in a vehicle infotainment system.
Its principal system feature is the integrated two-band equalizer. Bass and tone can therefore be adjusted without external equalizer components, while the processor supports common control software across the product family. The three input selectors allow multiple source signals to be routed to the four-channel output architecture, and independent channel faders provide finer control of individual output levels.
The BD37521FS-E2 is intended for car-audio systems, where a 12 V vehicle battery is regulated down to a 7 V to 9.5 V analog supply. Its integrated processing reduces board area compared with separate input selectors and tone-control blocks. The -E2 ordering designation identifies the exact ROHM ordering configuration, while the FS family provides the underlying sound-processor functionality.
Typical deployments include factory-installed head units, navigation-audio systems, aftermarket vehicle receivers, and automotive audio interface modules. The processor is especially useful when the design must support several audio sources while retaining per-channel level adjustment and simple tone compensation for different cabin sizes or speaker systems.
When laying out a new board, preserve the pin assignments and analog signal paths defined by the ROHM datasheet. Input and output filtering, grounding, and power-supply decoupling are central to avoiding audible noise or channel imbalance. Confirm the exact package dimensions, exposed pad requirements, control interface details, and absolute maximum ratings before releasing a production schematic or PCB footprint.
This product record combines the manufacturer product description with distributor package and feature information, then adds engineering-oriented application guidance, comparison criteria, and design checks. The BD37521FS-E2 is best understood as an integrated analog audio-routing and tone-control block rather than a power amplifier or audio codec.
Alternativas drop-in para BD37521FS-E2 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com BD37521FS-E2 (mesmo formato e footprint) — diferindo em Control Interface, Package, Product Type.
BD37511FS-E2
✅ Drop-In ⚠️ Especificações não verificadasConsulte o preço
Ver ficha técnica →BD37521FS-E1
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
BD37522FS-E2
✅ Drop-In ⚠️ Especificações não verificadasConsulte o preço
Ver ficha técnica →BD37526FS-E2
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
BD37531FS-E2
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
BD37521FS-E2 Classificações máximas e características elétricas
| Product Type | Sound Processor with Built-in 2-Band Equalizer |
| Manufacturer | ROHM Semiconductor |
| Supply Voltage Range | 7 V to 9.5 V |
| Control Interface | I2C bus |
| Equalizer Bands | 2 bands |
| Equalizer Functions | Bass and treble |
| Audio Input Channels | Stereo 4-channel input selector |
| Input Selectors | 3 selectors |
| Output Channel Control | 4-channel independent volume and fader control |
| Gain Control | Input-gain control |
| Main Volume Control | Main volume function |
| Loudness Control | Loudness function |
| Encapsulamento | 24-SSOP-A |
| Tipo de montagem | Surface mount |
Guia de Configuração de Pinos do BD37521FS-E2 24-ssop-a
Configuração de pinos para BD37521FS-E2 (pacote 24-ssop-a). Este componente analógico possui pinos de entrada, saída e alimentação. Consulte o datasheet do fabricante para configurações de offset null, compensação e pino de enable. Ideal para circuitos de condicionamento de sinal e amplificadores.
Nenhum dado detalhado de pinagem disponível para BD37521FS-E2.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
BD37521FS-E2 é adequado para 6 aplicaçãos: Automotive Head-Unit Signal Conditioning, Multi-Source Vehicle Radio, Navigation Audio Front-End, Aftermarket Automotive Receiver, Automotive Speaker-Balance Control, Automotive Audio Interface Module.
Automotive Head-Unit Signal Conditioning
The BD37521FS-E2 fits the central signal-conditioning stage of a vehicle head unit because it combines three input selectors, input-gain control, two-band bass-and-treble equalization, loudness, main volume, and four-channel fader control in one 24-SSOP-A device. It sits between the radio, navigation, media, and auxiliary sources and the external power-amplifier stage. This arrangement reduces discrete analog-control circuitry while preserving software control across the product family. The 7 V to 9.5 V operating range is appropriate for a regulated automotive-audio rail. Designers should still verify the exact input sensitivity, recommended filter network, control-register map, and thermal limits against the manufacturer datasheet before production release.
Recomendado
Multi-Source Vehicle Radio
A multi-source vehicle radio can use the BD37521FS-E2 to accept and route several stereo sources through one controlled audio path. Its three input selectors support source switching, while the built-in two-band equalizer allows bass and treble adjustment without an external tone-control network. Input gain, main volume, loudness, and independent four-channel fader control allow the radio to balance front and rear speakers for the vehicle cabin. The integrated approach is especially useful where PCB space is constrained and common control software is desired across related products. Before layout release, verify signal levels, grounding, connector routing, and each family member's exact source-selection behavior in the ROHM documentation.
Recomendado
Navigation Audio Front-End
Navigation-audio systems benefit from the BD37521FS-E2 because navigation prompts, radio, and media playback can be selected and level-adjusted before entering the vehicle's speaker-amplifier chain. The processor's two-band equalizer provides a compact means of tuning tonal balance for different speakers or cabin volumes, while loudness and four-channel fader functions add user control without requiring a separate control IC. Its 24-SSOP-A surface-mount package supports compact automotive circuit boards. A robust implementation must preserve low-noise analog routing and follow the datasheet's recommended input and output networks. The navigation processor or codec remains responsible for decoding, while the BD37521FS-E2 handles analog source selection and tone control.
Recomendado
Aftermarket Automotive Receiver
The BD37521FS-E2 is well suited to an aftermarket vehicle receiver that combines radio, auxiliary input, and digital media playback with front and rear speaker outputs. Three input selectors simplify source routing, while the internal two-band equalizer replaces a discrete bass-and-treble control network. Main volume, loudness, and four-channel fader control make it possible to balance individual speakers and compensate for cabin acoustics using the receiver's control software. The processor does not provide speaker drive, so a suitable power-amplifier stage must follow its outputs. The 7 V to 9.5 V operating range should be derived from the vehicle power system through an appropriately designed regulator, with input filtering and grounding validated for low audible noise.
Recomendado
Automotive Speaker-Balance Control
For four-speaker vehicle systems, the BD37521FS-E2 provides independent fader control that can reduce front-to-rear level imbalance and improve tonal integration between different speaker types. Its built-in equalizer lets the user tune bass and treble without changing passive crossover components, while loudness compensates for perceived low-frequency response at lower listening levels. This functionality is useful in compact vehicles, premium cabins, and designs with multiple driver sizes that have different sensitivities. Use the four-channel controls to establish appropriate source and output levels, and test the complete vehicle installation because speaker impedance, cabin acoustics, and amplifier gain affect the final result. The processor controls levels but does not replace the external power amplifiers.
Recomendado
Automotive Audio Interface Module
A compact automotive audio interface module can use the BD37521FS-E2 to add controlled tone, volume, loudness, and source-selection functions to an otherwise simple analog audio path. This is useful when integrating aftermarket speakers, navigation announcements, or external media players with an existing vehicle amplifier while retaining a common software-controlled user interface. The 24-SSOP-A package limits board area, and the internal equalizer removes the need for separate tone potentiometers and associated filtering. The module must provide regulated 7 V to 9.5 V power, stable ground references, input protection appropriate to the source, and output connections to the amplifier. Validate noise, channel separation, and control behavior across temperature and supply-voltage limits.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para BD37521FS-E2 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | BD37511FS-E2 | BD37521FS-E1 | BD37522FS-E2 | BD37526FS-E2 | BD37531FS-E2 |
|---|---|---|---|---|---|---|
| Package | 24-SSOP-A | 24-SSOP-A | 24-SSOP-A | 24-SSOP-A | 24-SSOP-A | 24-SSOP-A |
| Brand | ROHM Semiconductor | ROHM Semiconductor | ROHM Semiconductor | ROHM Semiconductor | ROHM Semiconductor | ROHM Semiconductor |
Principais diferenciais
- Integrates two-band tone control without external equalizer components (vs BD37521FS-E1)
- Supports three source selections with four-channel fader control (vs BD37511FS-E2)
- Centralizes input gain, main volume, loudness, and tone processing (vs BD37522FS-E2)
Notas de projeto
Route the three stereo input paths and four processed output paths as short, quiet analog traces, keeping switching-regulator paths and digital clock lines away from them. Follow the manufacturer application circuit for input and output component placement because filter stability, source impedance, and grounding determine channel balance. Use a continuous ground reference for the analog section and place the device's supply bypass capacitors at the package pins rather than at the regulator output.
Design the 7 V to 9.5 V supply for the complete automotive-audio subsystem, not only for nominal 12 V battery operation. Transients, cold-start behavior, regulator tolerance, and load variation can move the rail outside its supported range. Verify the manufacturer's absolute maximum and recommended operating values, then add suitable input protection and filtering. Keep the processor separated from high-current amplifier paths so their ground currents do not modulate the low-level audio reference.
Do not treat equalizer availability as proof that every family member is a drop-in replacement. Compare the exact pin names, analog-signal directions, I2C address, register defaults, and package drawing between the fitted device and any proposed substitute. Also distinguish the -E2 ordering code from other family suffixes. A mismatched control default can produce muted outputs or incorrect channel routing even when the PCB land pattern appears identical.
Validate the complete audio path for idle noise, channel separation, and switching clicks. Set input gains and output levels before enabling the loudness function and compare left and right channels with identical test signals. If clicks occur during selection or volume changes, inspect the I2C write sequence, mute timing, and external capacitor values against the recommended circuit. These measurements are more reliable than judging performance from the processor in isolation.
Informações de conformidade
The manufacturer identifies the device as intended for car audio, but the available product information does not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status.
