onsemi MJH11021

Overview

MJH11021 from onsemi is a PNP complementary Darlington silicon power transistor designed for high-voltage, high-current linear amplification and low-frequency switching in motor control and industrial power stages. It delivers V_CEO(sus) = 250 Vdc (min), I_C = 15 A continuous, and h_FE ≥ 400 at 10 A - enabling robust operation in 200–250 Vdc bus applications such as DC motor drives and relay drivers.

For engineers reviewing the MJH11021 datasheet, pinout, applications, or equivalent options, key selection criteria include its 250 V sustaining voltage rating, TO-247/TO-218 package thermal performance (R_JC = 0.83 °C/W), Darlington saturation behavior (V_CE(sat) = 2.5 V typ @ 10 A), and safe operating area under reverse-biased turn-off conditions.

Technical Context

The MJH11021 implements a monolithic Darlington pair with integrated base-emitter resistor network to ensure stable current gain and reduce external bias complexity. Its structure supports high DC current gain (h_FE ≥ 400 at 10 A) while maintaining low V_CE(sat) across wide temperature ranges (–65 °C to +150 °C).

It is rated for 250 Vdc collector-emitter sustaining voltage and exhibits Cob = 400–600 pF at V_CB = 10 Vdc, f = 0.1 MHz - confirming suitability for ≤100 kHz switching and high-voltage analog amplification where capacitive loading must be controlled.

Key Specifications

Pinout & Package

Package: TO-247 (Case 340L, Style 3) or TO-218 (SOT-93, Case 340D, Style 1), both Pb-free, with electrically isolated collector tab. Thermal resistance R_JC = 0.83 °C/W applies to both packages.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJH11019 and BDW93C, the MJH11021 uniquely combines 250 V sustaining voltage, 15 A continuous rating, and validated RBSOA - making it the only option among the three qualified for 240 Vac-derived 250 Vdc industrial motor and heater control.

Availability

MJH11021 is available at Aetrix Electronics and suitable for DC motor control, high-voltage relay driving, linear power amplification, and industrial heater regulation requiring stable component supply across extended production lifecycles.

Supply support for MJH11021 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 (Semiconductor Components Industries, LLC) is a global supplier of energy-efficient semiconductor solutions, specializing in power management, analog, sensors, and discrete devices for automotive, industrial, and cloud infrastructure markets.

The MJH11021 belongs to onsemi's complementary Darlington power transistor family, engineered specifically for high-reliability, high-voltage linear and switching applications in industrial motion control and power conversion systems.

FAQ

What is the maximum continuous collector current rating for MJH11021?

The MJH11021 is rated for 15 Adc continuous collector current at T_C = 25 °C. Derating is required above 25 °C at 1.2 W/°C, and actual usable current depends on heatsink design and ambient conditions. At T_C = 100 °C, the device supports approximately 6 A continuous without exceeding its 150 W total dissipation limit. The MJH11021 datasheet specifies this rating under defined thermal test conditions and must be verified in the final PCB layout.

Does MJH11021 have a built-in base-emitter resistor?

No, the MJH11021 does not integrate a base-emitter resistor. It is a monolithic Darlington pair requiring external base drive circuitry - typically a current-limited stage delivering 100 mA for 10 A collector conduction. Unlike some digital transistors, the MJH11021 relies on precise external bias control to maintain linearity and avoid thermal runaway, especially in linear amplifier applications. This design preserves flexibility for both switching and analog use cases.

Can MJH11021 be used in TO-247 and TO-218 packages interchangeably?

Yes, the MJH11021 is offered in both TO-247 (Case 340L) and TO-218 (SOT-93, Case 340D) packages with identical pinout (Base–Collector–Emitter–Collector), electrical specifications, and thermal resistance (R_JC = 0.83 °C/W). Mechanical mounting differs - TO-247 uses a single mounting hole, while TO-218 uses two - but both provide electrically isolated collector tabs and support the same 150 W power dissipation when properly heatsinked. The MJH11021G part number suffix denotes Pb-free compliance in either package.

What is the safe operating area (SOA) limitation for MJH11021 during reverse-biased turn-off?

The MJH11021 has a validated Reverse Bias Safe Operating Area (RBSOA) at T_C = 100 °C and 10% duty cycle, supporting simultaneous 250 V and 10 A during inductive turn-off when base-emitter is reverse-biased (V_BE(off) = 0–5.0 V). This rating assumes clamped conditions to prevent avalanche; unclamped inductive switching may exceed RBSOA limits. The MJH11021 SOA curves in Figure 5 of its datasheet define exact voltage–current boundaries for reliable operation in relay and motor control.

How does the DC current gain (h_FE) of MJH11021 vary with temperature and current?

The MJH11021 maintains h_FE ≥ 400 at I_C = 10 A and V_CE = 5 V across –55 °C to +150 °C, per Figure 6 of its datasheet. At lower currents (e.g., 1 A), h_FE rises to ~1000–1500, while at 15 A it drops to ≥100. Gain decreases with rising junction temperature but remains sufficient for Darlington drive integrity. For stable biasing, designers should reference the MJH11021 h_FE curve family rather than assuming fixed gain - critical for linear amplifier stability and thermal compensation.