STPA002OD-4WX - 4x52W Quad Class AB Audio Amplifier | STMicroelectronics
MPN: STPA002OD-4WX ✓ ActiveSTPA002OD-4WX Overview
A Class AB audio amplifier is a transistor-based power amplifier that conducts through both halves of its signal cycle. Relative to switching amplifiers, this architecture can provide a simpler signal path and controlled output-stage behavior, while the STPA002OD-4WX is specifically engineered to deliver high output current, manage distortion, and withstand automotive supply conditions. It belongs to the broader hierarchy of audio amplifiers, linear amplifiers, analog power amplifiers, and integrated circuits.
The manufacturer describes the STPA002 as a MOSFET Class AB audio power amplifier for high-power car radio. Its four-channel bridge configuration supports four x 52 W output capability, while standby and mute pins accept 3.3 V and 5 V logic. The device is designed for the low-voltage operating requirements of modern start-stop vehicles and can sustain hybrid-vehicle battery transitions. Its output stage is also reported as robust against several common fortuitous speaker misconnections.
Acoustic performance depends on correct analog implementation as well as the amplifier IC itself. The manufacturer datasheet recommends input capacitors having the same capacitance as the capacitor connected to the AC-GND pin for optimum pop performance. This matching requirement is important because startup and shutdown transients can propagate through the input network. Speaker load selection, power-supply stability, heat sinking, and the Flexiwatt25 thermal pad connection also determine whether the amplifier can sustain its rated output in a compact automotive enclosure.
Typical uses include automotive head-unit power stages, low-voltage car-radio systems, four-channel bridge-tied speaker drives, and aftermarket or OEM audio modules designed around start-stop battery systems. The four-output architecture simplifies board-level channel allocation compared with separate amplifier packages, provided the design includes adequate supply filtering, protection, and thermal management.
A key implementation trade-off is thermal capability. The 25-Flexiwatt package is intended to dissipate substantial heat, but the PCB must provide the manufacturer-recommended copper and thermal interface. Users should also verify speaker impedance, load configuration, supply limits, and automotive transient requirements against the current datasheet before production release, since those operating details are not included in the distributor snippets reviewed.
This product data combines the verified STMicroelectronics product description, distributor classification, package details, low-voltage control information, and pop-performance guidance with practical application and design guidance. It also distinguishes documented capabilities from parameters that still require confirmation from the manufacturer datasheet.
Drop-in alternatives for STPA002OD-4WX — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
STPA002OD-8WX
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STPA002D-4WX
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STPA002ODG-4WX
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STPA002OD-4WX Maximum Ratings & Electrical Characteristics
| Amplifier Type | Four-channel Class AB audio power amplifier |
| Output Configuration | Quad bridge |
| Number of Output Channels | 4 channels |
| Rated Output Power | 4 x 52 W |
| Output Stage Architecture | MOSFET Class AB |
| Package | 25-Flexiwatt vertical |
| Package Code | FM2 / ZFM |
| Number of Terminals | 25 terminals |
| Mounting Type | Through-hole |
| Standby Control Compatibility | 3.3 V compatible |
| Mute Control Compatibility | 5 V compatible |
| Primary Application | High-power automotive car radio |
| Start-Stop Vehicle Support | Supported for compliant low-voltage operation |
| Hybrid Battery Transition Support | Supported |
| Speaker Misconnection Robustness | Robust against several fortuitous misconnection types |
| Input Capacitor Matching | Equal to the capacitor connected to AC-GND for optimum pop performance |
STPA002OD-4WX fm2 / zfm Pin Configuration Guide
Pin configuration for STPA002OD-4WX (fm2 / zfm 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 STPA002OD-4WX.
Refer to the datasheet for full pin configuration.
Typical Applications
STPA002OD-4WX is suitable for 6 applications: Automotive Head-Unit Power Stage, Low-Voltage Start-Stop Car Radio, Four-Channel Bridge Speaker Drive, Automotive Aftermarket Radio, Hybrid Vehicle Audio Module, OEM High-Power Radio Module.
Automotive Head-Unit Power Stage
The STPA002OD-4WX fits a four-channel automotive head-unit power stage because it combines four Class AB outputs with a headline capability of 4 x 52 W in one 25-Flexiwatt package. Its MOSFET output stage is intended for high-power car-radio loads, while standby and mute inputs accept 3.3 V and 5 V logic commonly used by automotive head units. The principal design requirement is adequate thermal coupling between the Flexiwatt25 package and the PCB. Designers must also account for automotive supply transients, speaker impedance, and load configuration. Compared with using four separate power-amplifier packages, the quad-bridge arrangement reduces board area and simplifies channel allocation, but it concentrates heat in one power device and therefore requires careful copper and heat-path design.
Recommended
Low-Voltage Start-Stop Car Radio
The STPA002OD-4WX is specifically relevant to start-stop vehicle radio systems because STMicroelectronics states that it complies with current OEM specifications for low-voltage operation and can sustain hybrid-vehicle battery transitions. The four-channel amplifier provides 4 x 52 W capability under its specified test conditions, allowing one device to drive multiple speakers from a compact radio module. Its 25-Flexiwatt vertical package supports through-hole assembly, while standby and mute inputs compatible with 3.3 V and 5 V simplify connection to the radio's digital control circuitry. The engineering trade-off is that low-voltage automotive operation requires board-level protection and power-supply design that remains stable throughout engine start, shutdown, and battery-voltage transitions.
Recommended
Four-Channel Bridge Speaker Drive
The STPA002OD-4WX is suited to bridge-tied speaker systems requiring four independent Class AB outputs and up to 4 x 52 W per the manufacturer's specified conditions. Bridge operation increases voltage swing into the speaker compared with a conventional single-ended output, which can improve power utilization when the load impedance and supply conditions are appropriate. In a radio or compact sound system, the device can drive front-left, front-right, rear-left, and rear-right channels without four separate power packages. Standby and mute inputs provide system-level shutdown and click-control functions at 3.3 V and 5 V. However, speaker impedance must be verified against the datasheet, and the PCB must provide the recommended thermal interface because four active Class AB channels can generate substantial heat.
Recommended
Automotive Aftermarket Radio
The STPA002OD-4WX can serve as the central loudspeaker amplifier in an aftermarket automotive radio because it consolidates four Class AB channels into a single 25-Flexiwatt device and supports up to 4 x 52 W output under defined conditions. The through-hole 25-terminal package is suitable for conventional automotive radio PCB assembly, and its standby and mute inputs are compatible with 3.3 V and 5 V control levels. The amplifier also adds value where robustness to common speaker misconnections is important, as highlighted by STMicroelectronics. Designers should still include appropriate input filtering, supply decoupling, output protection, and thermal copper. The verified snippets do not provide full distortion or efficiency curves, so final speaker loading and headroom calculations must use the current manufacturer datasheet.
Recommended
Hybrid Vehicle Audio Module
The STPA002OD-4WX is a practical amplifier choice for a hybrid-vehicle audio module because STMicroelectronics specifically states that the STPA002 can sustain hybrid-vehicle battery transitions. Its four-channel, 4 x 52 W Class AB architecture supports a multi-speaker cabin audio design without requiring four separate output ICs. The low-voltage start-stop capability helps align the amplifier with vehicles where the radio must continue operating while engine state changes. Standby and mute control at 3.3 V and 5 V permits direct interfacing with common automotive control logic. The principal caveat is that hybrid battery transitions are a system-level requirement: the power supply, load dump protection, wiring, and amplifier must all be evaluated together. The manufacturer datasheet should define the exact electrical limits used for production validation.
Recommended
OEM High-Power Radio Module
The STPA002OD-4WX fits an OEM high-power radio module where four bridge-tied outputs, high current capability, and automotive environmental robustness are required. Its 4 x 52 W Class AB specification supports substantial loudspeaker output in a compact assembly, while the 25-Flexiwatt package consolidates four channels onto one PCB footprint. The manufacturer highlights robustness against several fortuitous misconnections, a useful attribute in automotive products where installation errors and speaker wiring faults are possible. A production design must implement the recommended input and AC-GND capacitor arrangement to minimize pop noise, particularly because the datasheet calls for equal capacitor values in those locations. Thermal performance should be validated across ambient temperature, speaker loading, supply voltage, and production tolerances.
Recommended
Recommended Products Summary
Engineering reference data for STPA002OD-4WX — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STPA002OD-8WX | STPA002D-4WX | STPA002ODG-4WX |
|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Package | Flexiwatt25 (FM2), 25 pins | Flexiwatt25 (FM2), 25 pins | Flexiwatt25 (FM2), 25 pins | Flexiwatt25 (FM2), 25 pins |
| Output Channels | 4 channels | 4 channels | 4 channels | 4 channels |
| Rated Output Power | 4 x 52 W | 4 x 52 W nominal family rating | 4 x 52 W nominal family rating | 4 x 52 W nominal family rating |
| Amplifier Class | Class AB | Class AB | Class AB | Class AB |
| Output Architecture | MOSFET Class AB quad bridge | MOSFET Class AB quad bridge | MOSFET Class AB quad bridge | MOSFET Class AB quad bridge |
| Standby and Mute Logic | 3.3 V standby and 5 V mute compatible | 3.3 V standby and 5 V mute compatible | 3.3 V standby and 5 V mute compatible | 3.3 V standby and 5 V mute compatible |
Key Differentiators
- Four integrated high-power Class AB channels (vs STPA002OD-8WX)
- Automotive low-voltage system alignment (vs STPA002D-4WX)
- Integrated standby and mute compatibility (vs STPA002ODG-4WX)
- Compact four-channel packaging (vs STPA002OD-8WX)
Design Notes
Treat the Flexiwatt25 package as a critical thermal element rather than merely a mechanical outline. The four-channel Class AB stage is specified for 4 x 52 W, but attainable output depends on speaker impedance, supply voltage, amplifier efficiency, PCB copper, ambient temperature, and the thermal interface to the board. Follow the manufacturer PCB and thermal-pad recommendations, keep the exposed area free of obstructing coating where required, and validate the assembly across maximum channel loading rather than relying on nominal power alone.
Match the value of each input capacitor to the capacitor connected to the AC-GND pin. The STMicroelectronics datasheet specifically recommends equal values for optimum pop performance, so independently selecting input and AC-GND capacitance can produce audible startup or shutdown transients. Check the actual application schematic and capacitor tolerance during design review, and include input bias, power-up sequence, standby, and mute tests in the prototype verification plan.
Design the vehicle power path and decoupling for low-voltage start-stop and hybrid battery transitions. Although the STPA002OD-4WX supports the relevant automotive operating concept, the amplifier cannot compensate for an unstable or unprotected supply. Use the manufacturer input-capacitor and application-circuit recommendations, verify local supply limits against the current datasheet, and validate operation during engine start, shutdown, and battery recovery. The reviewed data does not provide numerical supply or transient limits, so those values must not be guessed.
Keep the power-loop and sensitive input-return paths compact and follow the manufacturer's Flexiwatt25 layout drawing exactly. The output-current capability of the Class AB stage can create large ripple and electromagnetic emissions if supply and output paths are arranged with excessive loop area. Place input filtering and AC-GND components where shown in the application circuit, use low-ESR decoupling as specified, and avoid routing speaker outputs beneath the audio input and control sections.
Compliance Information
The verified sources identify automotive start-stop and hybrid battery-transition suitability but do not provide explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statements. These fields remain unknown rather than being inferred.
