MMBTA06LT1G - 80V 500mA NPN BJT Driver Transistor | onsemi
MPN: MMBTA06LT1G ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.18 | $0.18 |
| 10 | $0.15 | $1.50 |
| 100 | $0.1 | $10.00 |
| 500 | $0.07 | $35.00 |
| 1,000 | $0.05 | $50.00 |
| 3,000 | $0.04 | $120.00 |
MMBTA06LT1G Overview
A bipolar junction transistor (BJT) is a three-terminal semiconductor device in which a small base current controls a much larger collector current through the principle of current-controlled conduction. The NPN variant conducts when the base is pulled above the emitter by roughly 0.7V. BJTs sit within the broader transistor family alongside MOSFETs and IGBTs, and within the discrete-semiconductor category above diodes, providing amplification and saturated-switching functions in millions of analog and digital designs.
Key features of the MMBTA06LT1G include a VCEO rating of 80V, VCBO of 80V, and VEBO of 4V; continuous collector current of 500mA; a 100MHz current-gain bandwidth product (fT) that supports moderate-speed switching; and a maximum collector power dissipation of 225mW when properly derated across the -55C to +150C operating junction-temperature range. The Pb-free, halogen-free construction supports RoHS-compliant assemblies.
The device uses a planar epitaxial silicon process and the industry-standard SOT-23 footprint, which permits direct drop-in substitution on existing PCB land patterns. The 100MHz fT and 100 hFE at 100mA place it firmly in the small-signal general-purpose category rather than high-frequency or power-switching use.
Typical applications include MOSFET gate drivers, relay and solenoid drivers, interface logic level shifters, signal amplification, DC-DC converter pass elements, and LED drivers. The 80V collector rating provides substantial headroom for inductive loads such as relays and small motors.
When designing with this part, ensure that average collector dissipation stays below 225mW with appropriate copper-foil area or thermal vias, and place a base series resistor to limit base current during saturated switching. For higher-current or higher-voltage alternatives, onsemi also offers the MMBTA06LT3G (same die, different reel quantity) and the SMMBTA06LT1G automotive-grade version.
This page consolidates onsemi distributor pricing, drop-in alternatives, application guidance, and design notes that complement, and extend beyond, the manufacturer datasheet.
Drop-in alternatives for MMBTA06LT1G — 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:
MMBTA06LT3G
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SMMBTA06LT1G
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PMBTA06
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SMBTA06
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FMMT620
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MMBTA06LT1G Maximum Ratings & Electrical Characteristics
| Transistor Type | NPN |
| Polarity | NPN |
| Collector-Emitter Voltage (Vceo) | 80 V |
| Collector-Base Voltage (Vcbo) | 80 V |
| Emitter-Base Voltage (Vebo) | 4 V |
| Continuous Collector Current (IC) | 500 mA |
| Power Dissipation (Max) | 225 mW |
| Transition Frequency (ft) | 100 MHz |
| DC Current Gain (hFE) Min | 100 @ IC=100mA, VCE=1V |
| Operating Junction Temperature | -55C to +150C |
| Package | SOT-23-3 (TO-236) |
| Mounting Type | Surface Mount |
| Pin Count | 3 |
| RoHS Status | Compliant (Pb-Free, Halogen-Free) |
| AEC-Q101 Qualified | Yes (SMMBTA06LT1G variant) |
MMBTA06LT1G Pin Configuration
| Pin 1 | Base — Control terminal; current applied here controls collector current |
| Pin 2 | Emitter — Current exit terminal; typically tied to ground or low side of load |
| Pin 3 | Collector — Current entry terminal; connected to load or supply |
Typical Applications
MMBTA06LT1G is suitable for 6 applications: MOSFET Gate Driver, Relay and Solenoid Driver, Logic Level Shifter, Small-Signal Amplifier, LED Driver, DC-DC Converter Pass Element.
MOSFET Gate Driver
The MMBTA06LT1G serves as an effective low-side NPN gate driver for small-to-medium power MOSFETs in switching power supplies, motor-control H-bridges, and DC-DC converters. With a 500mA continuous collector current and 100MHz transition frequency, it delivers sufficient peak gate-charge current to switch MOSFETs at frequencies from a few kilohertz up to several hundred kilohertz, while the 80V VCEO rating provides substantial headroom for gate-drive transients above the MOSFET drain voltage. The device is typically configured in common-emitter with the collector tied through a resistor to the gate, and the base driven from a logic-level PWM source via a series resistor. Compared to using the logic output directly, this adds drive strength and level-shifting capability without requiring a dedicated gate-driver IC, making it popular in cost-sensitive designs. The SOT-23 footprint saves board area and allows placement close to the MOSFET gate for minimal parasitic inductance.
Recommended
Relay and Solenoid Driver
The MMBTA06LT1G is well matched to driving small relays, solenoids, and similar inductive loads from low-voltage logic. Its 500mA collector current comfortably exceeds the coil current of most signal relays and small solenoids, while the 80V VCEO rating provides more than enough headroom to withstand the inductive kick when the coil is de-energized (with a flyback diode). A typical circuit places the relay coil between V+ and the collector, with a base resistor limiting base current to a few milliamps from the microcontroller GPIO. The 100 hFE minimum means a 5mA base current can switch a 500mA load with margin. The SOT-23-3 package simplifies PCB layout in dense control boards where multiple relay drivers are required. Adding a freewheeling diode across the coil is mandatory to protect the BJT from reverse-voltage transients during switching.
Recommended
Logic Level Shifter
The MMBTA06LT1G provides a simple, low-cost solution for level shifting between logic domains of differing voltages, such as 3.3V microcontrollers driving 5V or 12V peripherals. In a common-collector (emitter-follower) configuration, the emitter voltage follows the base voltage minus one VBE drop, providing a shifted output. Alternatively, in common-emitter configuration, the transistor inverts and level-translates the input logic level. The 80V collector rating supports shifting to virtually any low-voltage logic standard, while the 500mA output capability allows direct drive of LEDs, optocouplers, or low-power logic inputs. The high fT of 100MHz ensures clean switching edges up to several megahertz, suitable for SPI, UART, and other moderate-speed digital interfaces. Compared to dedicated level-shifter ICs, this discrete approach costs less and offers flexibility in voltage selection.
Recommended
Small-Signal Amplifier
The MMBTA06LT1G functions as a general-purpose small-signal amplifier for audio pre-amplification, sensor signal conditioning, and IF stages in communication receivers. With hFE of 100 at 100mA and a transition frequency of 100MHz, it provides usable gain from DC up to several megahertz in common-emitter or common-base configurations. The 4V VEBO rating requires careful bias design to avoid base-emitter reverse breakdown in AC-coupled circuits with large input swings. Compared to specialized low-noise audio transistors like the 2N5089, the MMBTA06LT1G is not optimized for ultra-low-noise audio but provides more than adequate performance for general-purpose amplification. The SOT-23-3 package simplifies prototyping and high-density PCB layouts. Designers should AC-couple the input to set a stable bias point with emitter degeneration for predictable gain.
Recommended
LED Driver
The MMBTA06LT1G serves as a constant-current LED driver for indicator LEDs, panel illumination, and optocoupler input stages. With 500mA of available collector current, it can drive single high-brightness LEDs or small parallel LED arrays directly. The high current gain (hFE=100) means that a base current of just a few milliamps from a microcontroller GPIO or logic-level source can control hundreds of milliamps through the LED. The 80V VCEO rating allows the LED to be powered from high-voltage rails for efficient series-string designs. A typical circuit uses the transistor in common-emitter with the LED on the collector, a base resistor for current setting, and an optional emitter resistor for feedback. PWM dimming up to several kilohertz is supported cleanly thanks to the 100MHz fT.
Recommended
DC-DC Converter Pass Element
The MMBTA06LT1G is used in linear and quasi-switched DC-DC converter topologies as a series-pass element for low-current regulation. Its 80V rating and 500mA current capability make it suitable for post-regulation following switching regulators, where low ripple and fast transient response are required. While not as efficient as a switching regulator for high step-down ratios, a BJT-based linear regulator provides cleaner output with no switching noise, ideal for powering RF, analog, and audio circuits from a higher-voltage rail. The 225mW power dissipation rating limits use to applications where the VIN-VOUT differential multiplied by load current stays below this limit with adequate thermal relief. For higher power requirements, designers should consider Darlington pairs or dedicated linear regulators.
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Recommended Products Summary
Engineering reference data for MMBTA06LT1G — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MMBTA06LT3G | SMMBTA06LT1G | PMBTA06 | SMBTA06 |
|---|---|---|---|---|---|
| Package | SOT-23-3 (TO-236) | SOT-23-3 (TO-236) | SOT-23-3 (TO-236) | SOT-23-3 (TO-236) | SOT-23-3 (TO-236) |
| Brand | onsemi | onsemi | onsemi | NXP Semiconductors | Infineon |
| VCEO Max | 80 V | 80 V | 80 V | 80 V | 80 V |
| Collector Current Max | 500 mA | 500 mA | 500 mA | 500 mA | 500 mA |
| Power Dissipation | 225 mW | 225 mW | 225 mW | 250 mW | 330 mW |
| Transition Frequency (fT) | 100 MHz | 100 MHz | 100 MHz | 100 MHz | 100 MHz |
| hFE Min @ 100mA | 100 | 100 | 100 | 100 | 100 |
| Automotive Qualified (AEC-Q101) | No | No | Yes | No | No |
Key Differentiators
- AEC-Q101 automotive qualification available in same package (vs SMMBTA06LT1G)
- Higher voltage rating than MMBTA05 family (vs MMBTA05LT1G)
- Cross-brand drop-in availability from multiple manufacturers (vs PMBTA06 / SMBTA06)
Design Notes
At a 500mA collector current and 80V collector voltage, instantaneous power can reach 40W if saturated switching is not used. In linear operation, ensure the product of IC and VCE stays within the 225mW continuous power rating. SOT-23-3 thermal resistance (theta_JA) is typically 300-400 C/W on a standard JEDEC test board, meaning the junction temperature can rise 70-100C above ambient at full rated dissipation. For applications approaching the power limit, use larger copper pours or thermal vias to the opposite board layer. Avoid operating continuously near the SOA boundary; pulsed operation tolerates much higher peak dissipation than DC ratings suggest.
The SOT-23-3 land pattern should follow the JEDEC standard recommendation with pad dimensions of approximately 0.8mm x 0.9mm and 0.95mm pitch. Place the base resistor as close as possible to the base pin to minimize parasitic inductance in high-speed switching applications. For switching circuits above 100kHz, use a ground plane on the layer beneath the transistor to reduce EMI and provide thermal relief. Keep the collector trace short and wide when driving inductive loads to minimize voltage overshoot during switching transitions. A small copper pour connected to the collector pin serves double duty as both a heatsink and a low-impedance power trace.
Do not exceed the 4V VEBO rating - applying more than 4V of reverse bias between base and emitter can permanently damage the device. When switching inductive loads, always include a flyback diode or transient voltage suppressor across the coil to protect the collector from inductive kick-back. Calculate base resistor values using the worst-case minimum hFE (100), not the typical value, to ensure adequate drive into saturation across all units. Avoid operating in the linear region near the maximum power dissipation for extended periods - saturated switching is far more efficient and keeps the transistor within its SOA. For high-frequency applications above 50MHz, consider the parasitic capacitances between junctions, which can cause self-oscillation in poorly designed layouts.
Compliance Information
Pb-Free and Halogen-Free per onsemi datasheet. SMMBTA06LT1G variant is AEC-Q101 qualified for automotive use.