SMMBTA56LT1G - 80V PNP Driver BJT 500mA | onsemi SOT-23
부품 번호: SMMBTA56LT1G ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $0.18 | $0.18 |
| 10 | $0.16 | $1.60 |
| 100 | $0.12 | $12.00 |
| 500 | $0.09 | $45.00 |
| 1,000 | $0.07 | $70.00 |
SMMBTA56LT1G 개요
A bipolar junction transistor (BJT) is a three-terminal semiconductor device consisting of an emitter, base, and collector, in which a small base current controls a much larger collector current. The PNP variant conducts when the base is pulled below the emitter, enabling low-side switching of loads tied to a positive rail. BJTs sit in the broader taxonomy: PNP transistor -> BJT -> bipolar device -> discrete semiconductor. They remain preferred over MOSFETs for low-cost analog amplification, saturation-mode switching, and high-current linear regulation where their current-handling per unit area is favorable.
Key differentiating specifications: 80V collector-emitter breakdown gives wide margin above 24V industrial rails; 500mA continuous collector current handles relays, solenoids, and LED strings; 50MHz transition frequency supports medium-speed switching such as PWM audio or low-frequency SMPS drivers; and SOT-23-3 footprint enables compact PCB designs. The 225mW power dissipation requires thermal management via copper pours rather than large heatsinks.
Technically, the SMMBTA56LT1G uses an epitaxial planar construction with the S-prefix marking indicating onsemi's automotive-grade qualification (AEC-Q101) and PPAP capability, distinct from the MMBTA56 series. The device is Pb-Free, Halogen Free/BFR Free, and RoHS compliant, with MSL 1 moisture sensitivity enabling unlimited floor-life storage.
Typical applications include automotive load drivers (relays, lamps, solenoids), industrial control switching, linear amplifiers, MOSFET gate drivers, level shifters, and general-purpose switching circuits where compact SOT-23 packaging and automotive-grade reliability are required. Compared to its MMBTA56 predecessor, the SMMBTA56LT1G adds AEC-Q101 qualification and PPAP support.
A key design consideration: PNP transistors at 500mA in SOT-23 typically require thermal relief - at full load the 225mW dissipation can push junction temperature near limits, so designers should allocate copper area or limit continuous duty cycle. This part is intended for low-power surface mount applications where its SOT-23 footprint is acceptable.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single source for parametric comparison, sourcing decisions, and PCB layout guidance.
드롭인 대체품: SMMBTA56LT1G — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MMBTA56LT1G
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MMBTA56LT3G
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SMMBTA56LT3G
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MMBTA56LT1
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
PMBTA56
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SMMBTA56LT1G 최대 정격 & 전기적 특성
| 트랜지스터 유형 | PNP |
| 패키지 | SOT-23-3 (TO-236) |
| 실장 유형 | Surface Mount |
| 컬렉터-이미터 전압 (Vceo) | 80 V |
| Continuous Collector Current (IC) | 500 mA |
| Power Dissipation (PD) | 225 mW |
| 전이 주파수 (ft) | 50 MHz |
| 동작 온도 범위 | -55C to +150C (junction) |
| Automotive Qualified | Yes (AEC-Q101, PPAP capable) |
| Lead-Free / Halogen-Free | Yes (Pb-Free, Halogen Free/BFR Free) |
| RoHS Compliance | RoHS Compliant |
| MSL (Moisture Sensitivity Level) | MSL 1 (Unlimited floor life) |
SMMBTA56LT1G 핀 구성
| 핀 1 | Base — Control input - small base current modulates collector current |
| 핀 2 | Emitter — Current source - typically tied to VCC for PNP low-side switching |
| 핀 3 | Collector — Current output - switched load typically connects between collector and GND |
일반적인 애플리케이션
SMMBTA56LT1G 적합 용도: 6 애플리케이션s: Automotive Load Driver (Relay/Solenoid), Industrial Control Switching, P-Channel MOSFET Gate Driver, Linear Amplifier / Signal Conditioning, Level Shifter / Logic Translator, LED Driver / Display Backlight Control.
Automotive Load Driver (Relay/Solenoid)
The SMMBTA56LT1G is well suited as a low-side switch for automotive relays, solenoids, and small motors where its 500mA collector current handles typical coil loads directly and 80V VCEO provides margin against automotive load-dump transients up to 40V. Its AEC-Q101 qualification satisfies OEM automotive reliability requirements, and PNP polarity enables direct interface with 12V battery rails through a low-side MOSFET or BJT driver. Per onsemi datasheet application guidance, the device is housed in SOT-23 for compact body-electronics modules where PCB area is at a premium.
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Industrial Control Switching
In industrial 24V control systems, the SMMBTA56LT1G serves as a logic-level interface between microcontrollers and higher-current loads. Its 80V VCEO withstands 24V rails with 50% safety margin while 500mA collector current drives small pneumatic valves, indicator lamps, and optocoupler LED arrays. The 50MHz transition frequency supports PWM dimming of indicator LEDs and proportional valve control up to several kHz. AEC-Q101 qualification provides extended reliability margin beyond standard industrial temperature requirements.
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P-Channel MOSFET Gate Driver
The SMMBTA56LT1G functions as a PNP gate driver for P-channel MOSFETs in low-side switch configurations, where its 500mA collector current rapidly charges the MOSFET gate capacitance for fast switching transitions. With 50MHz fT it produces sub-microsecond switching times, reducing switching losses in PWM motor drives and DC-DC converters. Its 80V rating provides ample margin above 24V and 48V bus voltages common in industrial and telecom power systems. Per onsemi application notes, this topology reduces overall BOM cost versus dedicated MOSFET driver ICs.
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Linear Amplifier / Signal Conditioning
The SMMBTA56LT1G operates in linear amplifier configurations for sensor signal conditioning and audio pre-amplification stages. With 50MHz transition frequency, it provides wide small-signal bandwidth suitable for audio frequency amplification and instrumentation signal chains. PNP polarity complements NPN devices in push-pull output stages and differential amplifiers. AEC-Q101 qualification enables automotive sensor interface designs where amplifier stages must operate reliably across -40C to +125C automotive temperature grades.
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Level Shifter / Logic Translator
In mixed-voltage logic systems, the SMMBTA56LT1G performs logic level translation between lower-voltage microcontrollers and higher-voltage peripheral signals. Its 80V VCEO tolerates legacy 24V or 36V logic rails while the base input interfaces with 3.3V or 5V CMOS logic through appropriate base resistors. With 50MHz bandwidth, level shifting operates at speeds compatible with SPI, I2C, and UART signal rates, enabling seamless communication between modern low-voltage MCUs and industrial-grade 24V peripherals.
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LED Driver / Display Backlight Control
The SMMBTA56LT1G drives LED strings and display backlights where its 500mA collector current accommodates multi-LED arrays directly without additional driver stages. PNP polarity suits common-anode LED configurations where the LED string ties to VCC and the transistor switches the low side. With 50MHz transition frequency, PWM dimming operates smoothly across the full 0-100% duty cycle range at audible-immune frequencies above 20kHz, eliminating flicker in lighting and signage applications.
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추천 제품 요약
엔지니어링 참조 데이터: SMMBTA56LT1G — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MMBTA56LT1G | MMBTA56LT3G | SMMBTA56LT3G | PMBTA56 |
|---|---|---|---|---|---|
| Package | SOT-23-3 (TO-236) | SOT-23-3 (TO-236) - same | SOT-23-3 (TO-236) - same | SOT-23-3 (TO-236) - same | SOT-23-3 (TO-236) - same |
| Brand | onsemi | onsemi | onsemi | onsemi | Nexperia |
| Transistor Polarity | PNP | PNP | PNP | PNP | PNP |
| VCEO (Collector-Emitter Voltage) | 80 V | 80 V | 80 V | 80 V | 80 V |
| Continuous Collector Current | 500 mA | 500 mA | 500 mA | 500 mA | 500 mA |
| Automotive Qualified (AEC-Q101) | Yes | No (industrial grade) | No (industrial grade) | Yes | No (verify Nexperia variant) |
| Reel Quantity (LT1 vs LT3) | 3000 (7-inch reel) | 3000 (7-inch reel) | 10000 (13-inch reel) | 10000 (13-inch reel) | Verify per reel |
주요 차별점
- AEC-Q101 automotive qualification with PPAP support (vs MMBTA56LT1G)
- Pb-Free and Halogen-Free construction (vs MMBTA56LT1)
- Wider sourcing options across onsemi family (vs PMBTA56 (Nexperia))
설계 노트
Estimated: at 500mA continuous collector current and 2V VCE(sat), power dissipation reaches ~1W, exceeding the 225mW SOT-23 rating. In practice, the part is derated strongly with copper area; follow onsemi's thermal derating curves (typically 1.6 mW/C above 25C ambient). For 500mA continuous duty, allocate at least 100 sq mm of 2oz copper on the collector pad and limit ambient to below 70C, or reduce duty cycle to avoid thermal runaway. The SOT-23-3 package relies entirely on PCB copper for heat dissipation.
Use a star-ground topology tying emitter, base bias network, and load ground returns to a single point to prevent ground bounce from corrupting the base drive signal. Keep base trace short and direct, with the base resistor placed within 5mm of the base pin to minimize parasitic inductance. The collector pad serves as both electrical connection and primary thermal path - maximize copper area on this pad per onsemi land pattern recommendations.
Do not exceed VCEO (80V) or VCBO (verify datasheet) under any transient condition, including inductive flyback from relay/solenoid loads - always add a flyback diode across inductive loads in parallel with the coil, cathode to VCC. Do not drive the base from a high-impedance source above 5V without a current-limiting resistor; base current should be limited to approximately IC/10 to IC/50 for saturation. Verify pin orientation: Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector (per JEDEC TO-236AB) - reversed installation destroys the device instantly.
규정 준수 정보
AEC-Q101 (automotive BJT qualification, equivalent intent to AEC-Q100). Pb-Free, Halogen Free/BFR Free per onsemi datasheet. MSL 1 unlimited floor life simplifies manufacturing logistics. RoHS3 compliant per PartGenie.