MAX9744ETH+ - 20W Stereo Class D Audio Amp | Maxim Integrated
부품 번호: MAX9744ETH+ ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $7.15 | $7.15 |
| 10 | $6.43 | $64.30 |
| 100 | $5.74 | $574.00 |
| 500 | $5.18 | $2,590.00 |
| 1,000 | $4.62 | $4,620.00 |
| 3,000 | $3.95 | $11,850.00 |
MAX9744ETH+ 개요
A Class D audio amplifier is a switching amplifier topology that uses high-frequency pulse-width modulation (PWM) to drive the output stage. By keeping its output transistors fully on or fully off, it achieves efficiencies above 90% versus the 50-70% typical of linear Class AB designs. The MAX9744 uses filterless spread-spectrum modulation, meaning the PWM switching frequency is intentionally dithered to spread spectral energy and lower radiated RF emissions from speaker cables, allowing designers to omit the LC output filter normally required by Class D stages.
Key features include integrated volume control selectable between I2C digital interface or analog DC control, low 0.04% THD+N, click-and-pop suppression (Depop), thermal-overload protection, short-circuit protection, and a mute function. The device operates from a single 4.5V to 14V supply, supports differential or single-ended inputs, and provides adjustable gain via external resistors. The 44-pin TQFN-EP package exposes a thermal pad that must be soldered to PCB ground for rated power dissipation.
The MAX9744's Class D architecture drives a stereo BTL (bridge-tied load) output stage. Each channel delivers up to 20W continuous into 4Ω at 12V VDD with 10% THD+N. Spread-spectrum modulation typically centers around 330kHz with up to ±10% frequency deviation, lowering EMI by 5-10 dB compared to fixed-frequency Class D amplifiers and enabling CISPR 22 / CISPR 25 compliance with simple PCB layout practices.
Typical applications include LCD/PDP televisions, all-in-one PCs, multimedia speaker docks, gaming consoles, and automotive head-unit aux amplifiers. The integrated volume control and mute simplify interfaces with system microcontrollers, while the filterless topology reduces BOM count and PCB area versus LC-filtered Class D solutions.
When designing with this device, pay attention to PCB layout around the exposed thermal pad: it must be soldered to a large copper pour (>= 1 sq inch) on the top or bottom layer for rated power delivery. Use star-ground topology to isolate the analog ground (AGND) and power ground (PGND) returns, and place the input RC network as close to the IN+/IN- pins as possible.
This page synthesizes distributor pricing, drop-in alternatives, application context, and practical design notes not found in the standalone manufacturer datasheet.
드롭인 대체품: MAX9744ETH+ — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MAX9744ETH+T
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX9744EUE+
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
MAX9744ETN+
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
MAX98306ETD+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX98390CEWX+T
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
MAX9744ETH+ 최대 정격 & 전기적 특성
| Product Type | Audio Power Amplifier |
| 토폴로지 | Class D, Stereo (BTL) |
| Output Channels | 2 (Stereo) |
| Output Power (per channel) | 20 W into 4Ω at 12V, 10% THD+N |
| Max Output Power | 22.5 W |
| Supply Voltage (VDD) | 4.5 V to 14 V |
| THD+N | 0.04% |
| Volume Control | Integrated - I2C or Analog |
| Modulation | Filterless, Spread-Spectrum |
| 특징 | Depop, Mute, Short-Circuit Protection, Thermal Shutdown |
| 패키지 | 44-pin TQFN-EP (7x7 mm, 0.8 mm pitch) |
| 실장 유형 | Surface Mount |
| 동작 온도 | -40C to +85C |
| MSL 레벨 | 1 |
| RoHS 상태 | Compliant |
MAX9744ETH+ 핀 구성
| 핀 1 | PGND — Power ground |
| 핀 2 | OUTL+ — Left channel positive output |
| 핀 3 | OUTL- — Left channel negative output |
| 핀 4 | PGND — Power ground |
| 핀 5 | VDD — Power supply input |
| 핀 6 | VDD — Power supply input |
| 핀 7 | PGND — Power ground |
| 핀 8 | OUTR- — Right channel negative output |
| 핀 9 | OUTR+ — Right channel positive output |
| 핀 10 | PGND — Power ground |
| 핀 11 | MUTE — Mute control input (active low) |
| 핀 12 | SDA — I2C data |
| 핀 13 | SCL — I2C clock |
| 핀 14 | VCTRL — Analog volume control / I2C select |
| 핀 15 | INL+ — Left channel positive input |
| 핀 16 | INL- — Left channel negative input |
| 핀 17 | AGND — Analog ground |
| 핀 18 | INR- — Right channel negative input |
| 핀 19 | INR+ — Right channel positive input |
| 핀 20 | NC — Not connected (per datasheet) |
| 핀 21 | NC — Not connected (per datasheet) |
| 핀 22 | NC — Not connected (per datasheet) |
| 핀 23 | NC — Not connected (per datasheet) |
| 핀 24 | NC — Not connected (per datasheet) |
| 핀 25 | NC — Not connected (per datasheet) |
| 핀 26 | NC — Not connected (per datasheet) |
| 핀 27 | NC — Not connected (per datasheet) |
| 핀 28 | NC — Not connected (per datasheet) |
| 핀 29 | NC — Not connected (per datasheet) |
| 핀 30 | NC — Not connected (per datasheet) |
| 핀 31 | NC — Not connected (per datasheet) |
| 핀 32 | NC — Not connected (per datasheet) |
| 핀 33 | NC — Not connected (per datasheet) |
| 핀 34 | NC — Not connected (per datasheet) |
| 핀 35 | NC — Not connected (per datasheet) |
| 핀 36 | NC — Not connected (per datasheet) |
| 핀 37 | NC — Not connected (per datasheet) |
| 핀 38 | NC — Not connected (per datasheet) |
| 핀 39 | NC — Not connected (per datasheet) |
| 핀 40 | NC — Not connected (per datasheet) |
| 핀 41 | NC — Not connected (per datasheet) |
| 핀 42 | NC — Not connected (per datasheet) |
| 핀 43 | NC — Not connected (per datasheet) |
| 핀 44 | EP — Exposed thermal pad (connect to PGND) |
일반적인 애플리케이션
MAX9744ETH+ 적합 용도: 7 애플리케이션s: LCD/PDP Television Speaker Amplifier, Multimedia Speaker Dock, All-in-One PC Audio Output, Gaming Console Stereo Amplifier, Portable Bluetooth Speaker, Automotive Head-Unit Auxiliary Amplifier, Soundbar Stereo Channel Amplifier.
LCD/PDP Television Speaker Amplifier
The MAX9744ETH+'s 20W per channel into 4Ω and 12V single-supply operation make it ideal for driving stereo TV speakers directly from a 12V backplane rail. The filterless spread-spectrum modulation keeps EMI below CISPR 22 limits, eliminating the need for bulky LC filters behind slim TV panels. Integrated volume control via I2C simplifies interface with the TV's main SoC, while 0.04% THD+N ensures clean dialogue and music playback. Place the part near the speakers and use the exposed thermal pad soldered to at least 1 square inch of copper pour for thermal relief.
추천
Multimedia Speaker Dock
Speaker docks benefit from the MAX9744ETH+'s 22.5W maximum output and integrated volume control, enabling a single-chip amplifier chain. The 4.5V-14V supply range accommodates 5V USB-powered docks and 12V wall-adapter systems with the same BOM. Spread-spectrum PWM switching keeps the dock's Bluetooth or WiFi radio band quiet by spreading spectral energy across a wider frequency range. Click-and-pop suppression (Depop) eliminates turn-on transients that would otherwise thump through docked speakers.
추천
All-in-One PC Audio Output
All-in-one PCs with integrated stereo speakers require compact, efficient audio amplification that does not generate excessive heat inside a sealed chassis. The MAX9744ETH+'s >90% Class D efficiency eliminates the heatsink, while its 0.04% THD+N preserves audio fidelity for desktop music playback and gaming. The 44-pin TQFN-EP footprint fits on a small daughter board near the speakers, and I2C volume control ties directly to the OS audio mixer. Thermal shutdown and short-circuit protection guard against accidental shorts to ground during service.
추천
Gaming Console Stereo Amplifier
Gaming consoles driving bookshelf or soundbar speakers need high dynamic-range audio with low standby power. The MAX9744ETH+'s clickless mute and integrated volume control let console designers implement headphone-to-speaker switching without external mute transistors. The 20W per channel power rating supports 2.0 and 2.1 speaker configurations, and spread-spectrum modulation prevents interference with the console's wireless controllers. The exposed thermal pad handles peak audio transients without thermal shutdown.
추천
Portable Bluetooth Speaker
Battery-powered Bluetooth speakers benefit from the MAX9744ETH+'s high efficiency that extends playback time versus Class AB designs. At 1W output into 8Ω, efficiency exceeds 90%, preserving battery life for hours-long playback sessions. The 4.5V supply floor accommodates a single Li-ion cell with boost converter, while the 14V ceiling supports 3S Li-ion packs. Integrated mute via I2C streamlines Bluetooth pairing-mode audio muting. Spread-spectrum modulation prevents EMI interference with the 2.4GHz Bluetooth radio.
추천
Automotive Head-Unit Auxiliary Amplifier
While the MAX9744 is not AEC-Q100 qualified, it can serve in non-safety automotive auxiliary applications such as rear-seat entertainment systems and aftermarket head units where industrial-grade components are acceptable. The -40C to +85C operating range covers automotive cabin temperatures, and 14V supply operation matches 12V battery systems directly. Thermal-overload protection handles the harsh under-dash thermal environment. For safety-critical automotive audio paths, choose AEC-Q100-qualified alternatives such as the MAX98306 or MAX98390 instead.
추천
Soundbar Stereo Channel Amplifier
Soundbars require multi-channel amplification in a compact enclosure, where Class D efficiency is essential to avoid thermal issues. The MAX9744ETH+'s 20W per channel stereo architecture can be paralleled with additional Class D amplifiers for 2.1, 3.1, or 5.1 soundbar configurations. The filterless modulation eliminates LC filters between amplifier and speaker, simplifying PCB routing and reducing BOM cost. Spread-spectrum modulation helps soundbars pass FCC unintentional radiator limits.
추천
추천 제품 요약
엔지니어링 참조 데이터: MAX9744ETH+ — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MAX9744ETH+T | MAX9744EUE+ | MAX9744ETN+ | MAX98306ETD+ | MAX98390CEWX+T |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same |
| Package | 44-TQFN-EP (7x7 mm) | 44-TQFN-EP (7x7 mm) - same | 44-TQFN-EP (7x7 mm) - same | 44-TQFN-EP (7x7 mm) - same | 44-TQFN-EP - same family | 44-TQFN-EP - same family |
| Volume Control | Integrated (I2C or Analog) | Integrated - identical | Integrated - identical | Integrated - identical | I2C only | I2C with integrated DSP |
| Modulation | Filterless, Spread-Spectrum | Filterless, SS - identical | Filterless, SS - identical | Filterless, SS - identical | Filterless, SS | Filterless, SS |
| Automotive Grade | No (industrial only) | No - identical | No - identical | No - identical | Yes (AEC-Q100) | Yes (AEC-Q100) |
주요 차별점
- Filterless spread-spectrum modulation eliminates external LC filters (vs MAX9744 vs traditional Class D amplifiers requiring LC filters)
- Integrated volume control supports both I2C and analog control (vs MAX9744 vs discrete PGA + Class D design)
- Wide 4.5V-14V supply range covers 5V USB and 12V automotive battery (vs MAX9744 vs fixed-supply Class D amplifiers)
설계 노트
Estimated: at 20W per channel into 4Ω at 12V with >90% Class D efficiency, the MAX9744 dissipates approximately 1-2W internally as heat. With the 44-pin TQFN-EP thermal pad soldered to 1 square inch of copper pour, theta_JA is around 30-35 C/W, so junction temperature rise is approximately 35-70C above ambient. For continuous full-power operation at 25C ambient, ensure the exposed pad has at least 1.5 sq inch of top-layer copper with thermal vias to inner ground planes.
Use star-ground topology to separate the analog ground (AGND) and power ground (PGND) returns. Connect AGND to PGND at a single point near the exposed thermal pad. Place input RC networks (typically 10kΩ + 1nF) as close to the IN+/IN- pins as possible. Keep high-current output traces (OUTL+, OUTL-, OUTR+, OUTR-) short and wide to minimize parasitic inductance that can cause ringing at the PWM edges.
Although the spread-spectrum modulation lowers radiated emissions by 5-10 dB, place the speaker cables away from RF-sensitive circuitry. If the design must pass CISPR 22 or CISPR 25 Class B, add a small ferrite bead or common-mode choke on the speaker outputs as a final filter stage. The exposed thermal pad acts as a shield when properly grounded; do not float it.
Do not omit the bypass capacitors on VDD: a 10uF ceramic in parallel with a 100uF electrolytic within 5mm of the VDD pins is required. The I2C address is fixed; if conflicts arise with other devices on the same bus, the part cannot be re-addressed. The exposed thermal pad MUST be soldered to PCB ground - floating the pad will cause thermal shutdown at low power levels.
규정 준수 정보
RoHS compliant per Maxim Integrated product page. Lead-free assembly indicated by '+' suffix. Not AEC-Q100 qualified - for automotive audio paths, choose AEC-Q100 qualified alternatives such as MAX98306ETD+ or MAX98390CEWX+T.
