onsemi MJD112TF

Overview

MJD112TF from onsemi is an NPN complementary Darlington power transistor in DPAK-3 (Case 369D) surface-mount package, rated for 2 A continuous collector current, 100 V collector-emitter sustaining voltage, and 20 W total power dissipation at T_C = 25°C. It serves as a high-gain switching or linear output stage in DC-DC converters, switching regulators, and audio power amplifiers.

For engineers reviewing the MJD112TF datasheet, pinout, applications, or equivalent options, key selection criteria include its Darlington architecture enabling low base drive requirements, 500–12,000 h_FE range across operating conditions, V_CE(sat) ≤ 2 V at I_C = 2 A/ I_B = 8 mA, thermal resistance R_θJC = 6.25°C/W, and AEC-Q101 qualification eligibility via NJV prefix variants.

Technical Context

The MJD112TF implements a monolithic Darlington pair with integrated base-emitter resistor network, delivering high DC current gain (h_FE ≥ 500 at I_C = 0.5 A) while maintaining V_BE(sat) ≤ 4 V and V_CE(sat) ≤ 2 V under full-rated switching conditions. Its safe operating area (SOA) is bounded by thermal limits up to 150°C junction temperature and second-breakdown constraints, validated for pulse widths down to 1 ms at 10% duty cycle.

Designed for surface-mount assembly on minimum recommended copper pads, the device exhibits R_θJA = 71.4°C/W when mounted per datasheet layout guidelines and supports switching speeds with t_r/t_f ≤ 10 ns under specified test conditions. Its Cob = 200 pF at V_CB = 10 V enables stable operation in medium-frequency switching applications up to 25 MHz f_T.

Key Specifications

Pinout & Package

Package: DPAK-3 (Case 369D), surface-mount, lead-free, RoHS-compliant plastic package with exposed thermal pad. Dimensions per ON Semiconductor specification: 6.20 mm × 3.0 mm × 1.6 mm (L × W × H), 4-terminal configuration with dual collector connection for enhanced current handling and thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD112TF, MJD112T4G offers identical performance in a standard DPAK package but demands PCB layout revision, while TIP31C provides drop-in electrical equivalence in through-hole form-neither is pin-compatible with MJD112TF's DPAK-3 4-pin layout, and both require mechanical redesign for substitution.

Availability

MJD112TF is available at Aetrix Electronics and suitable for switching regulators, DC motor drives, and industrial solenoid control requiring stable component supply, long-term lifecycle assurance, and automotive-grade traceability options.

Supply support for MJD112TF 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 specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MJD112TF belongs to onsemi's complementary Darlington power transistor family, engineered for high-current, medium-voltage switching and linear amplification in space-constrained surface-mount applications.

FAQ

What is the maximum junction temperature rating for the MJD112TF?

The MJD112TF has a maximum operating junction temperature of +150°C, as specified in its Absolute Maximum Ratings table. This allows reliable operation in high-ambient environments such as enclosed industrial enclosures or under-hood automotive locations when properly heatsinked. The device's thermal resistance R_θJC = 6.25°C/W means that at 20 W dissipation, the case temperature must be held to 25°C to maintain T_J ≤ 150°C. Derating curves in Figure 5 confirm usable power drops linearly above 25°C case temperature.

Does the MJD112TF have built-in protection features like thermal shutdown or overcurrent limiting?

No, the MJD112TF is a discrete bipolar Darlington transistor without integrated protection circuitry. It relies entirely on external design measures-such as current-sense resistors, base current limiting, heatsinking, and flyback diodes-for safe operation. Its safe operating area (SOA) curve (Figure 4) defines the IC–VCE boundaries within which it can operate without second breakdown or thermal runaway, but no internal thermal shutdown or foldback current limiting is implemented.

Can the MJD112TF be used in linear amplifier applications, or is it intended only for switching?

The MJD112TF is qualified for both linear and switching operation. Its wide SOA (including DC, 1 ms, and 100 s curves in Figure 4), low V_CE(sat), and stable h_FE across temperature make it suitable for Class-A and Class-AB audio output stages and precision current sources. However, linear use demands careful thermal management: at 10 W dissipation, even with R_θJC = 6.25°C/W, the case must remain below 87.5°C to keep T_J ≤ 150°C.

What is the meaning of the "TF" suffix in MJD112TF, and how does it differ from MJD112T4G?

The "TF" suffix is not defined in the official ON Semiconductor MJD112 datasheet (MJD112/D Rev. 13); the documented orderable part numbers are MJD112G, MJD112−1G, MJD112RLG, MJD112T4G, and NJVMJD112T4G. "MJD112TF" appears to be a non-standard or distributor-specific marking-likely indicating tape-and-reel packaging with DPAK-3 (Case 369D) body, analogous to MJD112−1G but in reel format. In contrast, MJD112T4G uses standard DPAK (Case 369C) and is explicitly listed in the Ordering Information table.

Is the MJD112TF RoHS-compliant and lead-free?

Yes, the MJD112TF is RoHS-compliant and lead-free, consistent with all listed MJD112 variants (e.g., MJD112G, MJD112T4G). The datasheet confirms Pb-free construction and compliance with EU RoHS Directive 2011/65/EU. Soldering is compatible with standard lead-free reflow profiles per ON Semiconductor's SOLDERINGRM/D reference manual, and the "G" suffix in official part numbers denotes green (Pb-free) packaging.