Diodes Incorporated MMDT3904-7

Overview

MMDT3904-7 from Diodes Incorporated is a dual NPN small-signal transistor in SOT-363 package, rated for 40 V V_CEO, 200 mA I_C, and 200 mW P_D, optimized for low-power amplification and switching in space-constrained PCBs such as portable audio preamps and LED driver bias stages.

For engineers reviewing the MMDT3904-7 datasheet, MMDT3904-7 pinout, MMDT3904-7 application, or MMDT3904-7 equivalent, key selection criteria include verified h_FE range (40–300 at I_C = 100 µA to 100 mA), V_CE(SAT) ≤ 0.30 V at I_C = 50 mA, f_T = 300 MHz, and dual-die thermal coupling in shared SOT-363 footprint.

Technical Context

This dual NPN device uses epitaxial planar die construction with isolated junctions on a single SOT-363 substrate, enabling independent biasing of each transistor while sharing thermal mass. Its 300 MHz f_T and 5.0 dB NF at 1 kHz support RF preamplifier and low-noise analog front-end use.

Switching performance is defined by t_d/t_r/t_s/t_f = 35/35/200/50 ns under V_CC = 3.0 V, I_C = 10 mA conditions, with C_ibo = 8.0 pF and C_obo = 4.0 pF confirming suitability for <100 MHz digital logic interfacing and signal routing.

Key Specifications

Pinout & Package

Package: SOT-363 (SC-88), ultra-small surface-mount plastic case, UL 94V-0 rated, moisture sensitivity Level 1, 0.006 g weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DMN3020LSD-13 and BC846BPDW1T1G, MMDT3904-7 uniquely balances 200 mA I_C, 40 V V_CEO, and dual-transistor integration in SOT-363-making it optimal for mixed-signal designs requiring both amplification headroom and compact switching.

Availability

MMDT3904-7 is available at Aetrix Electronics and suitable for portable audio preamps, LED matrix drivers, digital level shifters, and current mirror references requiring stable component supply across industrial and consumer production cycles.

Supply support for MMDT3904-7 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 centers across Asia and manufacturing in China, Taiwan, and Germany.

The MMDT3904-7 belongs to Diodes' small-signal transistor product line, engineered specifically for space-constrained, low-power analog and digital interface applications where dual-device integration improves reliability and reduces PCB real estate.

FAQ

What is the maximum allowable junction temperature for MMDT3904-7?

The absolute maximum junction temperature is +150°C, consistent with its specified storage temperature range of –55°C to +150°C. Derating begins at T_A > 25°C per the 625°C/W R_JA curve in Figure 1, requiring P_D reduction of 0.32 mW/°C above ambient.

Is MMDT3904-7 suitable for linear amplifier operation?

Yes-its h_FE stability across I_C = 100 µA to 100 mA, 5.0 dB noise figure at 1 kHz, and 300 MHz f_T confirm suitability for Class-A audio preamplifiers and RF small-signal gain stages with proper biasing and thermal management.

How does the SOT-363 package affect thermal performance?

The SOT-363's 625°C/W R_JA reflects its ultra-small footprint and limited copper pad area. Performance matches the AP02001 recommended layout; doubling pad size or adding thermal vias can reduce R_JA by up to 25%, but is not validated in the official datasheet.

Does MMDT3904-7 have built-in ESD protection?

No-this device lacks integrated ESD protection diodes. Per Diodes Inc. documentation, external protection (e.g., 100 Ω series resistor + 10 nF bypass) is required for handling or board-level environments exceeding 2 kV HBM, especially at base terminals.