onsemi MPSA27RLRAG

Overview

MPSA27RLRAG from onsemi is an NPN silicon Darlington transistor in TO-92 package, rated for 60 V_CE, 500 mA continuous collector current, and 625 mW power dissipation at 25°C. It delivers DC current gain ≥10,000 at I_C = 10 mA and V_CE = 5 V, with V_CE(sat) ≤1.5 V at I_C = 100 mA/I_B = 0.1 mA - used in low-speed switching and high-gain amplification circuits such as relay drivers and sensor interface stages.

For engineers reviewing the MPSA27RLRAG datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE ≥10,000, Pb-free TO-92 packaging, V_CE breakdown ≥60 V, low saturation voltage under moderate drive, and thermal resistance of 200°C/W for ambient-limited linear operation.

Technical Context

The MPSA27RLRAG integrates two cascaded NPN transistors in a single TO-92 package to achieve ultra-high DC current gain without external biasing networks. Its Darlington configuration enables direct microcontroller GPIO driving of loads up to 500 mA while maintaining low base drive requirements (I_B ≤ 0.1 mA for full saturation).

It operates within –55°C to +150°C junction temperature range and exhibits low leakage: I_CBO ≤100 nA at V_CB = 50 V and I_CES ≤500 nA at V_CE = 50 V. Small-signal h_fe is 1.25–2.4 at 100 MHz, confirming limited RF suitability but robust low-frequency amplification capability.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-11), Pb-free, straight-lead or bent-lead orientation per tape-and-reel packaging (MPSA27RLRAG uses bent-lead configuration). Dimensions conform to ANSI Y14.5M with A = 4.45–5.20 mm height and lead pitch of 2.54 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA27RLRAG, MPSA28RLRAG trades gain for higher voltage tolerance, while ULN2003A offers integration and protection at the cost of analog performance and pin-level control - guiding selection toward voltage margin, channel count, or gain priority.

Availability

MPSA27RLRAG is available at Aetrix Electronics and suitable for relay driver circuits, sensor signal amplification, and LED array drivers requiring stable component supply, RoHS compliance, and long-term industrial availability.

Supply support for MPSA27RLRAG 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 delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The MPSA27RLRAG belongs to onsemi's general-purpose bipolar transistor product line, engineered for high-gain, low-speed switching and amplification in cost-sensitive, reliability-critical applications across industrial controls and instrumentation.

FAQ

What is the maximum collector-emitter voltage rating for the MPSA27RLRAG?

The MPSA27RLRAG has a guaranteed minimum collector-emitter breakdown voltage V(BR)_CEO of 60 V under test conditions (I_C = 100 mA, V_BE = 0). This rating applies to the MPSA27RLRAG specifically and allows safe operation in 24 V and 48 V systems with appropriate design margin. Exceeding this voltage risks avalanche failure even at low current.

Does the MPSA27RLRAG have a built-in base-emitter resistor?

No, the MPSA27RLRAG does not include any internal base-emitter resistor. It is a bare Darlington pair requiring external base current limiting - typically via a series resistor between the control source and pin 2 (base). This gives designers full flexibility in setting drive strength and response time, unlike integrated driver ICs such as the ULN2003A.

Is the MPSA27RLRAG pin-compatible with the MPSA27G variant?

Yes, the MPSA27RLRAG and MPSA27G share identical TO-92 mechanical dimensions, pinout (Emitter–Base–Collector), and electrical specifications. The only difference is packaging format: MPSA27RLRAG ships in 2000-unit tape-and-reel with bent leads, while MPSA27G is supplied in 5000-unit bulk packs with straight leads - both are Pb-free and electrically interchangeable.

What is the typical DC current gain of the MPSA27RLRAG at 100 mA collector current?

The MPSA27RLRAG guarantees h_FE ≥10,000 at I_C = 10 mA and V_CE = 5 V, but no minimum is specified at I_C = 100 mA. Per Figure 1 in the official datasheet, typical h_FE remains above 5,000 at 100 mA, though actual values vary by unit. For critical 100 mA gain-critical designs, validation testing of the MPSA27RLRAG batch is recommended.

Can the MPSA27RLRAG be used in linear amplifier configurations?

Yes, the MPSA27RLRAG can operate in linear (active) mode for low-frequency amplification, provided power dissipation stays within 625 mW at 25°C ambient and derated by 5 mW/°C above that. Its high h_FE and low leakage support stable biasing, but thermal runaway risk increases at elevated temperatures - use with emitter degeneration and thermal monitoring in sustained linear applications.