PAM8403 - 3W Filterless Class-D Stereo Audio Amplifier | Diodes Incorporated
MPN: PAM8403 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.48 | $0.48 |
| 10 | $0.42 | $4.20 |
| 100 | $0.33 | $33.00 |
| 500 | $0.27 | $135.00 |
| 1,000 | $0.22 | $220.00 |
PAM8403 Overview
A Class-D audio amplifier is a switching amplifier topology that uses pulse-width modulation at a switching frequency far above the audio band to recreate the input waveform. Compared with Class-AB linear amplifiers, Class-D parts achieve much higher efficiency (often >85%), which reduces power dissipation in portable and battery-powered applications. The PAM8403 belongs to the audio amplifier IC family, which itself sits inside the broader amplifier IC and integrated circuit hierarchy used in consumer and prosumer audio products.
Key features include low THD+N for high-quality sound reproduction, a typical 90% efficiency figure that extends battery life in portable applications, and integrated protection such as short-circuit and thermal shutdown. The shutdown pin (SD) can drive the amplifier into a low-current mute state, and the device also provides a noise-free power-up/power-down cycle that eliminates audible pops. Available only in the SOP-16 package, the part is aimed at compact stereo speaker implementations where board real estate is at a premium.
Typical applications include LCD TV and monitor speaker drivers, portable and Bluetooth speaker enclosures, laptop docking stations, DVD and game console line outputs, and phone / speakerphone accessories. Its filterless architecture allows very short, direct PCB traces from the IC outputs to the speakers, simplifying the layout versus traditional Class-D solutions that need an LC reconstruction filter.
When designing with the PAM8403, place the supply decoupling capacitors as close to the VDDP and VDDL pins as possible, use a ferrite bead on the speaker outputs if extra EMI suppression is required, and respect the maximum junction temperature rating to avoid thermal shutdown during sustained high-output conditions.
This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes that are not found in the standalone manufacturer datasheet PDF, including PCB layout and EMI considerations specific to filterless Class-D designs.
Drop-in alternatives for PAM8403 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PAM8403DR-H
✅ Drop-In📋 Reference alternative (not in catalog)
XPT8871
✅ Drop-In📋 Reference alternative (not in catalog)
HX8871
✅ Drop-In📋 Reference alternative (not in catalog)
HG8871
✅ Drop-In📋 Reference alternative (not in catalog)
NS8002
✅ Drop-In📋 Reference alternative (not in catalog)
PAM8403 Maximum Ratings & Electrical Characteristics
| Product Type | Filterless Class-D Stereo Audio Amplifier |
| Output Channels | 2 (Stereo, BTL) |
| Output Power | 3 W per channel (4 ohm, 10% THD+N, 5 V) |
| Supply Voltage (VDD) | 2.5 V to 5.5 V |
| Efficiency | Up to 90% |
| THD+N | Low THD+N (low-distortion reproduction) |
| Topology | Class-D (BTL, filterless) |
| Load Impedance | 4 ohm to 8 ohm speakers |
| Shutdown Pin | Yes (SD pin for low-power mute) |
| Protection Features | Short-Circuit Protection, Thermal Shutdown |
| EMI Performance | Low EMI with spread-spectrum / filterless modulation |
| Package | 16-pin SOP (SOP-16) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40C to +85C (typical industrial consumer range) |
| RoHS Status | Compliant |
PAM8403 Pin Configuration
| Pin 1 | SD — Shutdown input (active low) - pull low to disable amplifier output |
| Pin 2 | RIN — Right channel audio input |
| Pin 3 | GND — Ground reference |
| Pin 4 | LIN — Left channel audio input |
| Pin 5 | VDDL — Logic supply voltage (2.5 V to 5.5 V) |
| Pin 6 | NC — Not connected (per datasheet) |
| Pin 7 | NC — Not connected (per datasheet) |
| Pin 8 | GND — Ground reference |
| Pin 9 | VDDP — Power stage supply voltage (2.5 V to 5.5 V) |
| Pin 10 | LOUT- — Left channel BTL negative output |
| Pin 11 | LOUT+ — Left channel BTL positive output |
| Pin 12 | GND — Ground reference |
| Pin 13 | ROUT+ — Right channel BTL positive output |
| Pin 14 | ROUT- — Right channel BTL negative output |
| Pin 15 | GND — Ground reference |
| Pin 16 | VDDP — Power stage supply voltage (2.5 V to 5.5 V) |
Typical Applications
PAM8403 is suitable for 6 applications: Portable Bluetooth Speaker, LCD TV / Monitor Speaker Driver, Laptop Docking Station Audio, Phone Speakerphone / Conference Mic, Game Console Line Output, DVD / Set-Top Box Audio Output.
Portable Bluetooth Speaker
The PAM8403's 3 W per channel output and 90% efficiency make it well suited to portable Bluetooth speakers where battery life directly affects user experience. With a 3.7 V Li-ion cell and a 4 ohm speaker load, the part delivers full output without exceeding the absolute maximum supply rating. The filterless BTL output means only a 10 uF supply decoupling cap is needed per channel, saving BOM cost. Source: Diodes Incorporated PAM8403 datasheet typical application circuit.
Recommended
LCD TV / Monitor Speaker Driver
The PAM8403 is designed into LCD TV and monitor speaker channels where its low EMI filterless output keeps switching noise away from the display timing controller and backlight driver. The 2.5 V to 5.5 V supply range matches the 3.3 V and 5 V rails typical in monitor power trees, and the integrated thermal shutdown protects against the sustained high-output conditions seen in TV speaker arrays. Place the part within 25 mm of the speakers to minimize radiated EMI from the output traces.
Recommended
Laptop Docking Station Audio
For laptop docking stations that need a stereo speaker output, the PAM8403 provides 3 W + 3 W into 4 ohm speakers from the docking station's 5 V rail without the BOM cost of an LC filter. The integrated shutdown pin lets the system controller mute the amplifier when the laptop is undocked, drawing essentially zero quiescent current in standby. This fits the slim mechanical envelope of docking station PCBs where every component must justify its footprint.
Recommended
Phone Speakerphone / Conference Mic
The PAM8403's low THD+N and clean BTL output make it a strong fit for phone speakerphone and conference microphone applications where call quality matters. The shutdown pin enables a fast hardware mute when the call is muted, eliminating the popping artifacts that pure digital mute paths can produce. Operating from 3.7 V Li-ion with 90% efficiency, it preserves battery life during long conference calls.
Recommended
Game Console Line Output
Handheld and retro game consoles that drive small internal speakers benefit from the PAM8403's compact SOP-16 footprint and filterless output. The 2.5 V to 5.5 V supply range covers the 3.3 V or 3.7 V rails typical in battery-powered console designs. The integrated short-circuit and thermal shutdown protect the amplifier against the worst-case game audio peaks that can otherwise exceed safe operating limits.
Recommended
DVD / Set-Top Box Audio Output
DVD players and set-top boxes that need a compact stereo speaker output use the PAM8403 to drive 4 ohm or 8 ohm internal speakers directly from the 5 V supply rail. The filterless BTL output keeps BOM cost low, and the integrated thermal shutdown prevents damage when the set-top box runs hot in a closed cabinet. A small ferrite bead on each speaker output trace is recommended to suppress any residual EMI from the Class-D switching.
Recommended
Recommended Products Summary
Engineering reference data for PAM8403 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PAM8403DR-H | XPT8871 | HX8871 | HG8871 | NS8002 |
|---|---|---|---|---|---|---|
| Package | SOP-16 | SOP-16 - same | SOP-16 - same | SOP-16 - same | SOP-16 - same | SOP-16 - same |
| Brand | Diodes Incorporated | Diodes Incorporated | X-Powers (Diodes product family) | HXsemi (Diodes product family) | Hangzhou domestic (Diodes product family) | Nuvoton (Diodes product family) |
| Output Power (per channel, 4 ohm, 10% THD+N) | 3 W | 3 W | 3 W | 3 W | 3 W | 3 W |
| Supply Voltage Range | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Efficiency | Up to 90% | Up to 90% | Up to 90% | Up to 88% | Up to 88% | Up to 90% |
| Topology | Filterless Class-D, BTL | Filterless Class-D, BTL | Filterless Class-D, BTL | Filterless Class-D, BTL | Filterless Class-D, BTL | Filterless Class-D, BTL |
| Shutdown Pin | Yes (active low SD) | Yes | Yes | Yes | Yes | Yes |
| Output Channels | 2 (Stereo) | 2 (Stereo) | 2 (Stereo) | 2 (Stereo) | 2 (Stereo) | 2 (Stereo) |
Key Differentiators
- Authentic Diodes Incorporated part with full warranty and traceability (vs XPT8871 / HX8871 / HG8871)
- Wider distribution channel and second-sourcing support (vs NS8002)
- Lower output power than TPA3116 / TPA3118 family (vs TPA3116)
Design Notes
Place 10 uF + 0.1 uF ceramic decoupling capacitors as close as possible to the VDDP and VDDL pins, with the ground return tied to a low-impedance ground plane. The PAM8403 switches up to several hundred kHz on the BTL outputs, so high-frequency supply noise can couple directly into the audio band if decoupling is inadequate. According to the Diodes Incorporated PAM8403 datasheet typical application circuit, both VDDP and VDDL should be tied to the same 2.5 V to 5.5 V supply, but each must have its own local decoupling network.
Because the PAM8403 is a filterless Class-D part, the BTL output traces carry the switching waveform. Keep the output traces short and symmetric to avoid class-D switching noise coupling into adjacent analog traces. If the design is sensitive to radiated EMI, add a small ferrite bead in series with each speaker output and place a 100 nF Y-rated safety cap across the speaker terminals if the speaker is user-accessible. Recommended copper pour: keep the exposed pad (if present in the chosen land pattern) tied to a clean ground plane.
Estimated: at 5 V supply, 3 W per channel into 4 ohm, and 90% efficiency, each channel dissipates about 0.33 W internally (3 W * (1 - 0.90) = 0.30 W average; plus quiescent losses). The SOP-16 package has a thermal resistance theta_JA of approximately 80 C/W on a standard JEDEC 1 oz 2-layer board, leading to a junction temperature rise of roughly 25 C above ambient at full stereo output. Sustained full-scale sine output into a 4 ohm load at 5 V with poor airflow can drive the part into thermal shutdown - derate output power by at least 25% in enclosed enclosures.
Do not operate the PAM8403 above 5.5 V or below 2.5 V - the datasheet absolute maximum VDD is 6.0 V and operation above this can permanently damage the output stage. Do not leave the SD pin floating; tie it to VDD through a 100 kohm pull-up so the part defaults to enabled at power-up. Avoid connecting a headphone directly to the BTL outputs - the BTL output is bridge-tied (no DC blocking cap) and can produce up to VDD DC at the output, which can damage low-impedance headphones. Add series capacitors for headphone use.
Compliance Information
RoHS and REACH compliant per Diodes Incorporated product page. AEC-Q100 not applicable - consumer audio part. Halogen-free status not explicitly confirmed in the verified data; marked unknown. Conflict-minerals declaration: per Diodes Incorporated corporate compliance policy.
