Diodes Incorporated MMSTA13-7

Overview

MMSTA13-7 from Diodes Incorporated is an NPN surface-mount Darlington transistor in SOT-323 package, rated for 30 V V_CEO, 300 mA I_C, and 200 mW P_D, with minimum h_FE of 5,000 at 10 mA/5 V. It delivers high current gain and low saturation voltage for low-power switching and amplification in space-constrained consumer and industrial control circuits.

For engineers reviewing the MMSTA13-7 datasheet, MMSTA13-7 pinout, MMSTA13-7 application, or MMSTA13-7 equivalent, key selection criteria include verified Darlington configuration, SOT-323 thermal performance (R_θJA = 625 °C/W), V_CE(SAT) ≤ 1.5 V at 100 mA/100 µA drive, and RoHS-compliant green molding compound compliance per J-STD-020C Level 1 moisture sensitivity.

Technical Context

This device implements a monolithic epitaxial planar Darlington pair-two cascaded NPN transistors-with base-emitter shunt resistor omitted. Its high h_FE enables microampere-level base drive to switch 100 mA loads, while f_T = 125 MHz supports moderate-speed digital switching up to ~100 kHz without significant gain roll-off.

The SOT-323 package uses matte tin-plated Alloy 42 leads and UL 94V-0 green molding compound. Thermal derating follows a linear 0.8 mW/°C reduction above 25°C ambient, validated on FR-4 PCB per AP02001 pad layout.

Key Specifications

Pinout & Package

Package: SOT-323 - ultra-small plastic surface-mount case (2.20 × 1.35 × 0.90 mm max), UL 94V-0 rated, lead-free, green compound, moisture sensitivity Level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NSVT1300MT1G and ZTX1048A, MMSTA13-7 uniquely combines Darlington-level gain, SOT-323 miniaturization, and sub-1.5 V saturation in a single RoHS-compliant device-making it optimal for space- and drive-limited low-power switching where thermal budget is tight.

Availability

MMSTA13-7 is available at Aetrix Electronics and suitable for LED driver circuits, relay interfaces, thermal sensor amplifiers, and small-signal audio preamps requiring stable component supply across high-mix, low-volume production runs.

Supply support for MMSTA13-7 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, serving industrial, computing, consumer, and communications markets since 1969.

The MMSTA series belongs to Diodes' general-purpose bipolar transistor portfolio, designed specifically for high-gain, low-power switching and amplification in compact surface-mount applications where drive efficiency and thermal reliability are critical.

FAQ

What is the maximum safe operating temperature for MMSTA13-7?

The junction and storage temperature range is –55°C to +150°C. At 25°C ambient, maximum power dissipation is 200 mW; this derates linearly to zero at 150°C ambient, based on R_θJA = 625 °C/W and the AP02001 reference PCB layout. Exceeding 150°C junction temperature risks permanent parametric shift.

Does MMSTA13-7 require an external base resistor?

No. As a monolithic Darlington transistor, MMSTA13-7 integrates two cascaded NPN stages without base-emitter shunt resistors. It operates with direct base drive-no external resistor needed for standard switching applications. Base current must be limited only if driving from high-voltage sources (>10 V) to avoid exceeding I_B absolute maximum ratings.

How does MMSTA13-7 differ from MMSTA14-7?

MMSTA13-7 has minimum h_FE = 5,000 at 10 mA/5 V, while MMSTA14-7 guarantees h_FE ≥ 10,000 under identical conditions. Both share identical voltage/current ratings, package, and saturation characteristics. MMSTA14-7 is selected when tighter gain consistency or higher drive margin is required in precision analog or low-noise switching roles.

Is MMSTA13-7 suitable for PWM motor control?

Yes-for low-power brushed DC motors drawing ≤100 mA average current. Its 125 MHz f_T and 1.5 V V_CE(SAT) support PWM frequencies up to 20 kHz with minimal switching loss. However, thermal limits (200 mW P_D) restrict continuous operation above ~50 mA at elevated ambient temperatures; heatsinking or duty-cycle derating is required for sustained loads.