MMBF170LT1 - 60V 500mA N-Channel MOSFET SOT-23 | onsemi
MPN： MMBF170LT1 ✓ 啟用中MMBF170LT1 概覽
A power MOSFET is a voltage-controlled semiconductor switch used to amplify or switch electronic signals. The N-channel enhancement-mode type requires a positive gate-to-source voltage (VGS) above the threshold (typically around 1 V to 2 V) to turn on, and turns off when VGS returns to zero. Within the broader taxonomy, this part sits under discrete semiconductor -> MOSFET -> N-channel enhancement-mode -> small-signal/low-power MOSFET. Compared to bipolar transistors, MOSFETs offer higher input impedance, faster switching, and no gate current draw once the gate is charged.
Key features of the MMBF170LT1 include a 60 V drain-to-source voltage rating (VDSS), a continuous drain current of 500 mA at TA=25°C with a 225 mW power dissipation rating, and a low-threshold gate drive that makes it compatible with 3.3 V and 5 V logic. The SOT-23 package keeps the footprint small for portable and high-density PCB designs, and the device is available on tape and reel for automated assembly.
The internal construction uses DMOS cell technology to balance RDS(on) and switching losses. A low gate charge supports fast switching transitions in PWM and driver circuits, while the body diode enables use in low-side switching and level-shift topologies. The device is also designed to meet automotive-quality standards per the onsemi qualification flow.
Typical applications include load switching in portable and battery-powered equipment, LED drivers, level shifters, signal gating, and small motor or relay drivers. Because of its 60 V rating, it is also used in 12 V and 24 V industrial bus switching where headroom is needed for transients. Designers commonly use it as an interface between microcontrollers and higher-power loads such as solenoids, lamps, and small DC motors.
When designing with this part, observe the 225 mW power dissipation limit at TA=25°C and derate linearly to zero at the maximum rated junction temperature. Keep the gate drive rise/fall times fast to minimize switching loss, and place a gate-source resistor (typically 10 kΩ) on the gate to prevent unwanted turn-on from leakage or noise coupling. The exposed pad on SOT-23 packages is not present on this part, so thermal performance depends entirely on the drain, source, and gate lead copper area.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone. Engineers can use the comparison table to evaluate pin-compatible substitutes, and the FAQ section answers the most common commercial, technical, and replacement questions.
直接替換替代品，適用於 MMBF170LT1 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： MMBF170LT1 （相同外形與佔位） — 差異在於 Technology, Transistor Type, Continuous Drain Current (ID), RoHS Status, Package.
MMBF170LT1G
✅ 直接替換📋 參考替代品（不在目錄中）
MMBF170LT3G
✅ 直接替換📋 參考替代品（不在目錄中）
2N7002LT1G
✅ 直接替換聯絡詢價
查看資料表 →2N7002L
✅ 直接替換聯絡詢價
查看資料表 →BSS138LT1G
✅ 直接替換聯絡詢價
查看資料表 →2N7002-7-F
✅ 直接替換聯絡詢價
查看資料表 →MMBF170LT1 最大額定值與電氣特性
| Manufacturer | onsemi (ON Semiconductor) |
| Part Number | MMBF170LT1 |
| 電晶體類型 | N-Channel MOSFET, Enhancement Mode |
| Drain-Source Voltage (VDSS) | 60 V |
| Drain-Gate Voltage (VDGS) | 60 Vdc |
| Gate-Source Voltage - Continuous (VGS) | ±20 Vdc (per datasheet) |
| Gate-Source Voltage - Non-repetitive (VGSM) | ±40 Vpk (tp <= 50 ms) |
| Continuous Drain Current (ID) | 500 mA (Ta) |
| Total Device Dissipation (PD) | 225 mW (Ta, FR-5 board) |
| 工作溫度範圍 | -55 °C to +150 °C (TJ max per datasheet) |
| 封裝 / 外殼 | SOT-23-3 (TO-236) |
| 安裝類型 | Surface Mount |
| 腳位數 | 3 |
| RoHS 狀態 | Compliant (per onsemi product page) |
| AEC-Q101 Qualified | Yes (per datasheet) |
| Technology | DMOS |
| Polarity | N-Channel |
MMBF170LT1 腳位配置
| 腳位 1 | Gate — Gate control input - logic-level drive (3.3 V / 5 V compatible) |
| 腳位 2 | Source — Source terminal - typically tied to GND for low-side switching |
| 腳位 3 | Drain — Drain terminal - connected to the load |
安全工作區 (MMBF170LT1)
典型應用
MMBF170LT1 適用於 6 應用s: Low-Side Load Switching, LED Driver and Dimming, Logic Level Shifter, Battery-Powered Portable Equipment, Automotive 12 V Body Electronics, Signal Gating and Multiplexing.
Low-Side Load Switching
The MMBF170LT1's 60 V VDSS rating and 500 mA continuous drain current make it a strong fit for low-side switching of relays, solenoids, lamps, and small DC motors in 12 V and 24 V systems. Its logic-level gate threshold allows direct drive from 3.3 V or 5 V microcontroller GPIO pins without a dedicated gate-driver IC. Placed between the load and ground with the source tied to ground, the MOSFET adds minimal series resistance when fully enhanced, and its low gate charge supports PWM dimming and motor-speed control up to tens of kHz. Unlike a bipolar transistor, it draws no continuous base current once the gate is charged, reducing microcontroller GPIO loading.
推薦
LED Driver and Dimming
The MMBF170LT1 is commonly used as a constant-current LED driver in portable lighting, signage, and backlight applications. With 500 mA continuous drain current and 60 V VDSS, it can drive high-brightness LED strings from 12 V or 24 V supplies while leaving headroom for transients. Its fast switching enables PWM dimming at audio-band frequencies above the flicker perception threshold, with the logic-level gate driven directly from a microcontroller timer output. Compared to a BJT driver, the MOSFET eliminates base-current loss and produces less heat at the same LED current, simplifying thermal design in compact fixtures.
推薦
Logic Level Shifter
The MMBF170LT1 functions as a simple bidirectional logic level translator between low-voltage microcontrollers (3.3 V) and 5 V or higher-voltage peripherals. Two MMBF170LT1s wired in a back-to-back source-follower configuration create a passive level shifter that works for I2C, UART, and GPIO signals up to a few hundred kHz. The 60 V VDSS rating provides generous safety margin for 5 V, 12 V, and even 24 V translation. Engineers value this topology because it requires no level-shifter IC, draws no quiescent current, and uses parts that are already in the BOM for other switching functions.
推薦
Battery-Powered Portable Equipment
The MMBF170LT1 is well suited to portable, battery-powered applications such as handheld instruments, wearables, and IoT sensor nodes where quiescent current and footprint matter. Its low gate-charge characteristic enables microsecond switching transitions, minimizing the time the device spends in the linear region and reducing switching loss. With no continuous gate current draw once charged, it preserves battery life in always-on systems. The SOT-23-3 package keeps board space under 10 mm², allowing designers to add power-switching capability without enlarging the PCB, which is critical for compact wearables and small-form-factor IoT modules.
推薦
Automotive 12 V Body Electronics
AEC-Q101 qualification makes the MMBF170LT1 suitable for automotive body-electronics modules controlling interior lighting, seat heaters, mirror adjusters, and similar 12 V loads. The 60 V VDSS rating absorbs load-dump transients commonly present in automotive electrical environments, providing robust operation without an additional TVS protection device. Direct 3.3 V or 5 V microcontroller drive simplifies software-controlled load management. Compared to electromechanical relays, the solid-state MOSFET switching eliminates audible click noise and bounce, improving user experience in cabin electronics.
推薦
Signal Gating and Multiplexing
The MMBF170LT1 acts as a low-leakage analog signal gate in test equipment, audio multiplexers, and instrumentation front-ends. Its high off-state resistance and low on-state resistance produce a high on/off ratio when used to switch analog signals below its VDSS rating. The DMOS construction yields low gate-drain and gate-source capacitance, minimizing clock feedthrough in sample-and-hold or chopper-stabilized circuits. Engineers use it to multiplex analog signals from sensors to a single ADC channel, or to gate audio paths in mixers, where its low distortion preserves signal fidelity.
推薦
推薦產品摘要
工程參考資料，適用於 MMBF170LT1 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | MMBF170LT1G | MMBF170LT3G | 2N7002LT1G | 2N7002 | BSS138LT1G | 2N7002-7-F |
|---|---|---|---|---|---|---|---|
| Brand | onsemi | onsemi | onsemi | onsemi | onsemi | onsemi | Diodes Incorporated |
| Package | SOT-23-3 (TO-236) | SOT-23-3 - same | SOT-23-3 - same | SOT-23-3 - same | SOT-23-3 - same | SOT-23-3 - same | SOT-23-3 - same |
| Drain-Source Voltage (VDSS) | 60 V | 60 V | 60 V | 60 V | 60 V | 50 V | 60 V |
| Continuous Drain Current (ID) | 500 mA | 500 mA | 500 mA | 200 mA | 200 mA | 200 mA | 200 mA |
| Technology | DMOS | DMOS | DMOS | DMOS | DMOS | DMOS | DMOS |
| AEC-Q101 Qualified | Yes | Yes | Yes | Yes | No (legacy) | Yes | No |
| RoHS Status | Compliant | Compliant | Compliant | Compliant | Non-compliant (legacy) | Compliant | Compliant |
主要差異化特點
- 500 mA continuous drain current in SOT-23-3 (對比2N7002LT1G)
- AEC-Q101 qualified for automotive use (對比2N7002 (legacy))
- 60 V VDSS gives headroom over 50 V alternatives (對比BSS138LT1G)
設計說明
Estimated: at PD=225 mW (FR-5 reference board, TA=25°C), the MMBF170LT1 dissipates 225 mW with no heatsink. Above TA=25°C, power must be derated linearly toward TJ(max) per the onsemi datasheet. For continuous 500 mA operation in a small SOT-23-3 footprint, ensure adequate copper area on the drain and source pads to spread heat. If the application requires sustained currents near 500 mA in still air, consider a MOSFET in a larger package such as DPAK or SO-8 to reduce junction temperature rise.
Place the gate drive trace as short as possible to minimize parasitic inductance and capacitance, which can cause unwanted ringing during fast switching transitions. Add a 10 kΩ gate-source resistor to ensure the MOSFET stays off when the microcontroller GPIO is in high-impedance state during reset or power-up. For PWM dimming above 1 kHz, place a small RC snubber across drain-source if the load is inductive to control voltage transients and EMI.
Do not exceed the VGS rating of ±20 Vdc continuous or ±40 Vpk transient - use a gate-source zener or resistor divider if the driving signal can swing higher. Verify the SOT-23-3 pinout (Gate=1, Source=2, Drain=3 per the onsemi datasheet) against any cross-referenced footprint, since some manufacturers use a mirrored pinout for the same package. When driving an inductive load (relay coil, solenoid, motor), add a flyback diode across the load to protect the MOSFET from inductive kickback.
合規資訊
RoHS and REACH compliance per onsemi product page. AEC-Q101 automotive qualified per the MMBF170LT1 datasheet. Lead-free terminal finish with halogen-free molding compound per onsemi environmental compliance documentation.
