onsemi MMBTA05LT3

Overview

MMBTA05LT3 from onsemi is an NPN silicon small-signal transistor in SOT-23 package, rated for 60 V_CEO, 500 mA continuous collector current, and 225 mW power dissipation on FR-5 board. It delivers DC current gain (h_FE) ≥100 at I_C = 10 mA, V_CE = 1.0 V, and exhibits f_T = 100 MHz - used in low-power switching and amplification stages of sensor interface circuits, LED drivers, and logic-level translators.

For engineers reviewing the MMBTA05LT3 datasheet, pinout, applications, or equivalent options, key selection criteria include its 60 V breakdown rating, 100–300 h_FE range across operating current, SOT-23 thermal performance (R_JA = 556 °C/W), AEC-Q101 qualification status, and Pb-free RoHS-compliant packaging.

Technical Context

This NPN bipolar junction transistor operates in active and saturation regions with verified V_CE(sat) ≤ 0.25 V at I_C = 100 mA / I_B = 10 mA and V_BE(on) ≤ 1.2 V under same conditions. Its safe operating area supports single-pulse operation up to 100 V and 500 mA at T_A = 25°C, with thermal derating of 1.8 mW/°C above ambient.

The device features HBM Class 3B ESD robustness and is characterized across −55°C to +150°C junction temperature range. Electrical parameters are specified at TA = 25°C unless noted, with pulse test conditions (300 µs width, 2% duty cycle) applied for breakdown voltage measurements.

Key Specifications

Pinout & Package

SOT-23 (Case 318, Style 6) surface-mount plastic package with gull-wing leads; 2.90 mm × 1.30 mm × 0.95 mm footprint; Pb-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN small-signal transistor applications.

Compared with BC846BLT1G and PN2222A-AP, the MMBTA05LT3 offers AEC-Q101 qualification and optimized SOT-23 thermal resistance (556 °C/W) for automotive and industrial surface-mount applications, while maintaining compatible gain and speed for general-purpose switching.

Availability

MMBTA05LT3 is available at Aetrix Electronics and suitable for LED driver stages, microcontroller GPIO expansion, industrial sensor interfaces, and power supply enable switches requiring stable component supply and automotive-grade reliability.

Supply support for MMBTA05LT3 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, delivering power management, analog, sensing, and connectivity solutions.

The MMBTA05LT3 belongs to onsemi's broad portfolio of general-purpose bipolar transistors designed for cost-sensitive, high-reliability applications in automotive, industrial, and consumer systems.

FAQ

What is the maximum collector-emitter voltage rating for the MMBTA05LT3?

The MMBTA05LT3 has a guaranteed minimum collector-emitter breakdown voltage (V_(BR)CEO) of 60 Vdc at I_C = 1.0 mA and I_B = 0. This rating defines the absolute upper limit for voltage applied between collector and emitter in open-base conditions and must not be exceeded to prevent avalanche-induced damage. The MMBTA05LT3 is not rated for 80 V operation - that specification applies only to the MMBTA06L variant.

Is the MMBTA05LT3 suitable for automotive applications?

Yes, the MMBTA05LT3 is AEC-Q101 qualified and PPAP capable, with stress testing performed per automotive reliability standards including temperature cycling, high-temperature reverse bias, and mechanical shock. Its −55°C to +150°C junction temperature range and HBM Class 3B ESD rating make it appropriate for engine control modules, body electronics, and infotainment subsystems where the MMBTA05LT3 serves as a robust, surface-mount switching element.

What is the thermal resistance of the MMBTA05LT3 on a standard FR-5 PCB?

The MMBTA05LT3 has a thermal resistance from junction-to-ambient (R_JA) of 556 °C/W when mounted on a 1.0 × 0.75 × 0.062 inch FR-5 board at T_A = 25°C. This value assumes no additional copper pour or thermal vias. Derating is 1.8 mW/°C above 25°C ambient, meaning usable power dissipation drops to 135 mW at 90°C ambient - a critical constraint when designing the MMBTA05LT3 into thermally dense layouts.

Does the MMBTA05LT3 have a guaranteed DC current gain (h_FE) specification?

Yes, the MMBTA05LT3 guarantees h_FE ≥100 at I_C = 10 mA and V_CE = 1.0 Vdc, with typical values reaching 200–300 in production lots. This minimum gain is validated across the full −55°C to +150°C junction temperature range and supports stable bias design without external feedback or trimming. Gain is not specified at I_C = 100 mA in the official datasheet, so design margins must rely on the 10 mA condition.

What is the pin configuration of the MMBTA05LT3 in the SOT-23 package?

The MMBTA05LT3 uses standard SOT-23 pinout per onsemi's Style 6 designation: Pin 1 is Base, Pin 2 is Emitter, and Pin 3 is Collector. This matches JEDEC TO-236AB and is consistent across all MMBTA05L variants including MMBTA05LT1G and MMBTA05LT3G. Correct orientation is confirmed by the device marking "1H" adjacent to Pin 1 and the absence of polarity indicators - the MMBTA05LT3 is an NPN transistor requiring base-emitter forward bias for conduction.