onsemi MJE271

Overview

MJE271G from onsemi is a PNP complementary silicon power Darlington transistor in TO-225 package, rated for 100 V_CEO(sus), 2.0 A continuous collector current, and 15 W total power dissipation at T_C = 25°C. It delivers high DC current gain (h_FE ≥ 1500 at I_C = 120 mA, V_CE = 10 V) and supports robust linear and switching applications including audio output stages and relay drivers.

For engineers reviewing the MJE271G datasheet, pinout, applications, or equivalent options, key selection criteria include safe operating area (IS/B = 0.375 A at 40 V, 1.0 s), thermal resistance (R_JA = 83.3°C/W), V_EB = 5.0 Vdc max, f_T = 6.0 MHz, and Pb-free RoHS-compliant packaging.

Technical Context

The MJE271G is a monolithic PNP Darlington pair with integrated base-emitter resistor network enabling high current gain and simplified drive requirements. Its second-breakdown-limited SOA supports non-repetitive pulse operation up to 375 mA at 40 V for 1 second, critical for surge-tolerant power control.

Designed for complementary use with the NPN MJE270G, it shares identical TO-225 mechanical outline, thermal characteristics (R_JC = 8.33°C/W), and voltage ratings (V_CEO(sus) = 100 Vdc min, V_CB = 100 Vdc), ensuring matched performance in push-pull amplifier and H-bridge configurations.

Key Specifications

Pinout & Package

Package: TO-225 (Case 77-09, Style 3), thermally optimized plastic package with metal tab (pins 2 and 4 internally connected to collector and electrically tied to backside tab).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BD679A and TIP2955, the MJE271G provides superior safe operating area, higher DC gain, and guaranteed 100 V ruggedness - making it the preferred choice for 24–100 V industrial switching and audio output where drive efficiency and surge tolerance are critical.

Availability

MJE271G is available at Aetrix Electronics and suitable for audio amplifier output stages, industrial relay drivers, linear regulator pass elements, and DC motor control circuits requiring stable component supply and long-term manufacturability.

Supply support for MJE271G 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 manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and cloud power applications.

The MJE271G belongs to onsemi's complementary power Darlington transistor family, engineered for high-voltage, medium-current linear and switching applications where gain, ruggedness, and thermal reliability are essential.

FAQ

What is the maximum continuous collector current rating for the MJE271G?

The MJE271G is rated for 2.0 Adc continuous collector current at case temperature T_C = 25°C. Derating is required above this temperature at 0.12 W/°C. At ambient temperature T_A = 25°C, the rating drops to 1.5 Adc due to higher thermal resistance to ambient (R_JA = 83.3°C/W). Always verify junction temperature using actual PCB layout and heatsink conditions before final design validation of the MJE271G.

Is the MJE271G pin-compatible with the MJE270G?

No - the MJE271G (PNP) and MJE270G (NPN) share identical TO-225 package outline and pin numbering (Style 3), but their terminal polarities are reversed: MJE271G has Base–Collector–Emitter on pins 1–2/4–3, while MJE270G has Base–Collector–Emitter on pins 1–2/4–3 *with opposite semiconductor type*. They are complementary, not pin-swappable; substituting one for the other without circuit revision will cause functional failure. The MJE271G must be used in PNP-configured circuits only.

Does the MJE271G require a base resistor, and what value is recommended?

Yes - the MJE271G requires an external base current-limiting resistor to prevent excessive base current (I_B max = 0.1 Adc). For typical switching at I_C = 1.0 A with h_FE ≈ 1500, target I_B ≈ 0.7 mA. With V_BE(on) ≤ 2.0 V and driver voltage of 5 V, a 4.7 kΩ resistor provides appropriate bias. Always verify base drive under worst-case V_BE and h_FE min to ensure saturation across temperature and unit variation for reliable MJE271G operation.

Can the MJE271G be used in parallel for higher current handling?

Parallel operation of MJE271G devices is not recommended without individual emitter resistors and matched thermal mounting. Due to parameter spread in h_FE and V_BE(on), unequal current sharing can occur, leading to thermal runaway. If higher current is needed, select a single higher-rated device (e.g., MJ15003) or redesign with active current balancing. The MJE271G datasheet does not specify parallel-use guidelines, and onsemi does not endorse unbalanced paralleling - always validate thermal distribution empirically when considering MJE271G multi-unit configurations.

What is the meaning of the "G" suffix in MJE271G?

The "G" suffix in MJE271G denotes a Pb-free, RoHS-compliant package per EU Directive 2011/65/EU. It confirms that all solderable terminations and internal construction meet lead-free requirements, with no exemption claimed. This marking aligns with onsemi's standardized Pb-free indicator system and appears in the device marking as "JE271G" on the TO-225 body. The MJE271G is not a different electrical variant - its specifications and performance are identical to legacy MJE271 versions except for material content compliance.