Diodes Incorporated MMDT3904-7-F

Overview

MMDT3904-7-F from Diodes Incorporated is a dual NPN small-signal transistor in SOT363 package, rated for 40 V V_CEO, 200 mA I_C, and 200 mW power dissipation. It delivers h_FE = 40–300 (at I_C = 100 µA to 100 mA), V_CE(sat) ≤ 0.30 V (I_C = 50 mA), and f_T = 300 MHz - optimized for medium-power switching and amplification in space-constrained automotive and industrial control circuits.

For engineers reviewing the MMDT3904-7-F datasheet, MMDT3904-7-F pinout, MMDT3904-7-F application, or MMDT3904-7-F equivalent, key selection criteria include AEC-Q101 qualification, dual-transistor integration in ultra-small SOT363, guaranteed h_FE minima across five current levels, ESD robustness (4 kV HBM), and thermal performance validated at T_J = –55°C to +150°C.

Technical Context

This dual NPN transistor uses epitaxial planar die construction for stable gain and low leakage. Each transistor shares common emitter connections in the SOT363 package, enabling compact push-pull or differential pair configurations without discrete interconnects.

It operates reliably under pulsed conditions (≤300 µs pulse width, ≤2% duty cycle) for switching, with verified V_CEO = 40 V, BVCBO = 60 V, and VEBO = 6.0 V - supporting biasing flexibility in 3.3 V/5 V logic interfaces and 12 V automotive signal conditioning stages.

Key Specifications

Pinout & Package

SOT363 is a 6-pin ultra-small surface-mount package (2.15 mm × 2.10 mm × 1.00 mm) with gull-wing leads, matte tin terminations, and UL 94V-0 molded green compound. Pin 1 and Pin 2 serve as emitter and base of first NPN; Pin 5 and Pin 6 serve as emitter and base of second NPN; Pin 3 and Pin 4 are shared collectors.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DMT3904W-7-F and BC846BDW1T1G, MMDT3904-7-F uniquely balances AEC-Q101 compliance, 40 V rating, and broad h_FE range - making it optimal for cost-sensitive, space-constrained automotive body electronics where qualification and moderate gain variability are jointly required.

Availability

MMDT3904-7-F is available at Aetrix Electronics and suitable for automotive door modules, industrial PLC input stages, USB-C PD interface control, and medical infusion pump signal buffering requiring stable component supply across multi-year production cycles.

Supply support for MMDT3904-7-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

The MMDT3904 belongs to Diodes' AEC-Q101-qualified small-signal transistor product line, engineered specifically for automotive body electronics and industrial control systems demanding reliability, miniaturization, and RoHS/Green compliance.

FAQ

What is the maximum continuous collector current per transistor in MMDT3904-7-F?

The absolute maximum continuous collector current is 200 mA per transistor, as specified in the Absolute Maximum Ratings table. This rating applies at T_A = +25°C with proper PCB thermal relief; derating is required above 25°C ambient per the 625 °C/W R_θJA value and Fig. 1 power dissipation curve.

Does MMDT3904-7-F support simultaneous conduction of both transistors?

Yes - both NPN transistors operate independently with isolated bases (Pins 2 and 6) and emitters (Pins 1 and 5), while sharing collectors (Pins 3 and 4). This allows concurrent switching or amplification, provided total device power dissipation remains ≤200 mW and junction temperature stays within –55°C to +150°C limits.

How does the SOT363 package affect thermal performance compared to SOT23?

SOT363 has higher thermal resistance (R_θJA = 625 °C/W) than single-transistor SOT23 packages (~400–500 °C/W) due to dual-die integration and shared thermal path. Its compact size reduces board area but requires careful copper pour design and avoids dense component clustering to maintain safe T_J.

Is MMDT3904-7-F suitable for RF applications above 100 MHz?

Yes - its f_T = 300 MHz and low C_obo = 4.0 pF (at V_CB = 5 V) support use in VHF-band RF amplifiers and oscillator buffers. However, RF performance depends on external matching networks and PCB layout; the device is characterized for small-signal gain, not power-added efficiency or harmonic distortion.