onsemi MMBT3906T

Overview

MMBT3906T from ON Semiconductor is a PNP epitaxial silicon transistor designed for general-purpose amplification and switching in low-power circuits. It features a maximum collector-emitter voltage of −40 V, continuous collector current of 200 mA, DC current gain (hFE) up to 300 at IC = −0.1 mA, saturation voltage of −0.25 V at IC = −10 mA/IB = −1 mA, and operates across −55 °C to +150 °C junction temperature. It is widely used in portable electronics, signal inversion, and discrete logic interface stages.

For engineers reviewing the MMBT3906T datasheet, pinout, applications, or equivalent options, key selection criteria include its SOT-523F ultra-small package, complementary pairing with MMBT3904T, guaranteed hFE range across multiple bias points, low VCE(sat), and JESD22-A113B MSL 1 moisture sensitivity rating.

Technical Context

The MMBT3906T is a discrete bipolar junction transistor operating in common-emitter configuration with fixed PNP polarity. Its design supports both linear amplification (via hFE-controlled IC/IB ratio) and saturated switching (with verified VCE(sat) and storage time <225 ns).

It uses epitaxial base construction for improved high-frequency response (fT = 250 MHz at VCE = −20 V, IC = −10 mA) and low leakage (ICEX ≤ −50 nA at VCE = −30 V), while thermal resistance (RθJA = 500 °C/W) and power dissipation (PC = 250 mW) are defined for SOT-523F mounting on minimum land pads per JEDEC standards.

Key Specifications

Pinout & Package

SOT-523F is a 3-pin ultra-small surface-mount plastic package with gull-wing leads, UL V0 flammability rating, matte tin lead finish, and JESD22-A113B MSL 1 classification (unlimited floor life). Dimensions: 1.2 mm × 0.8 mm × 0.5 mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP transistor applications.

Compared with MMBT3906T, MMBT3906LT1G trades miniaturization for thermal headroom, while DXT3906-7 offers identical packaging with marginal capacitance trade-off-both require validation of hFE distribution and saturation behavior in target bias conditions.

Availability

MMBT3906T is available at Aetrix Electronics and suitable for portable power management, digital logic level shifting, and discrete load switching requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MMBT3906T 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MMBT3906T belongs to ON Semiconductor's general-purpose discrete transistor product line, engineered for high-volume, cost-sensitive applications where reliability, small size, and consistent parametric performance are critical.

FAQ

What is the maximum operating junction temperature for the MMBT3906T?

The MMBT3906T has a maximum junction temperature (TJ) rating of +150 °C, validated under steady-state conditions per its Absolute Maximum Ratings table. This allows reliable operation in sealed enclosures or near heat-generating components when mounted on standard PCB land patterns per JEDEC guidelines. Derating begins above +85 °C ambient, with full 250 mW power dissipation only guaranteed at Ta ≤ 25 °C. The MMBT3906T must not exceed TJ = +150 °C in any operating condition.

Is the MMBT3906T pin-compatible with the MMBT3904T?

No, the MMBT3906T is not pin-compatible with the MMBT3904T. While both use the SOT-523F package and share identical pinout (Emitter-Base-Collector), they are complementary devices-MMBT3906T is PNP and MMBT3904T is NPN-so their terminal polarities and biasing requirements differ fundamentally. Swapping them without circuit redesign will result in non-functional or damaged operation. The MMBT3906T datasheet explicitly recommends MMBT3904T as a complementary type, not a replacement.

Does the MMBT3906T support lead-free reflow soldering?

Yes, the MMBT3906T supports lead-free reflow soldering. Its terminals feature pure matte tin plating and comply with JESD22-A121 and MIL-STD-750 Method 2026 for solderability. With MSL 1 classification per JESD22-A113B, it requires no baking prior to reflow, and its plastic case (KTMC1060SC) is rated UL V0 for flammability. Peak reflow temperature must not exceed 260 °C for ≤10 seconds, consistent with IPC/JEDEC J-STD-020.

What is the typical storage time (ts) of the MMBT3906T in switching applications?

The MMBT3906T has a specified storage time (ts) of 225 ns under test conditions of VCC = −3 V, IC = −10 mA, and IB1 = −IB2 = −1 mA. This value reflects the time required for minority carriers to clear the base region after drive removal, directly impacting maximum usable switching frequency and PWM fidelity. For high-speed switching above 1 MHz, designers should verify actual ts in their specific layout and drive strength, as parasitic inductance and base resistance affect measured values. The MMBT3906T datasheet provides this parameter in its Electrical Characteristics table.

Can the MMBT3906T be used in RF amplifier stages?

Yes, the MMBT3906T can be used in low-power RF amplifier stages up to ~100 MHz, supported by its 250 MHz current-gain bandwidth product (fT) measured at VCE = −20 V, IC = −10 mA, and f = 100 MHz. Its 7.0 pF output capacitance (Cob) and 15 pF input capacitance (Cib) are well-characterized for impedance matching. However, it is not optimized for narrowband RF power amplification; for such applications, dedicated RF transistors with higher fT, lower noise figure, and specified S-parameters are recommended. The MMBT3906T is best suited for broadband preamplifiers and buffer stages.