onsemi MPSA28RLRP

Overview

MPSA28RLRP from onsemi is an NPN silicon Darlington transistor in TO-92 package, rated for 80 V_CE, 500 mA continuous collector current, and 625 mW power dissipation at T_A = 25°C. It delivers high DC current gain (h_FE ≥ 10,000 at I_C = 10 mA), low V_CE(sat) (≤ 0.7 V), and operates across −55°C to +150°C junction temperature - used in low-speed switching and signal amplification in industrial control interfaces.

For engineers reviewing the MPSA28RLRP datasheet, pinout, applications, or equivalent options, key selection criteria include its Darlington configuration, TO-92 mechanical compatibility, V_CE = 80 V rating, h_FE ≥ 10 k, and Pb-free RLRP packaging for automated assembly.

Technical Context

The MPSA28RLRP integrates two cascaded NPN transistors in a monolithic Darlington pair, providing high current gain with single-base control. Its internal structure enables low base drive requirements while maintaining defined saturation behavior (V_CE(sat) ≤ 0.7 V at I_C/I_B = 1000) and stable operation up to 150°C junction temperature.

It exhibits f_T = 125 MHz at I_C = 10 mA and V_CE = 5 V, supporting moderate-frequency switching. C_obo = 5.0 pF (typ) and V_(BR)EBO = 12 V define its small-signal integrity and reverse-bias safety margins under bias conditions.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-11), 3-lead through-hole plastic package with Emitter-Base-Collector pinout (pin 1 = Emitter, pin 2 = Base, pin 3 = Collector).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA28RLRP, MPSA29RLRP offers extended voltage headroom without layout change, while ULN2003A trades single-device simplicity for multi-channel integration and protection - both require functional validation but no pinout redesign.

Availability

MPSA28RLRP is available at Aetrix Electronics and suitable for industrial relay drivers, LED signage controllers, low-voltage power supplies, and automotive body control modules requiring stable component supply and Pb-free compliance.

Supply support for MPSA28RLRP 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 focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.

The MPSA28RLRP belongs to onsemi's general-purpose bipolar transistor product line, designed specifically for cost-sensitive, high-reliability discrete switching and amplification in industrial and automotive subsystems.

FAQ

What is the maximum collector-emitter voltage rating for the MPSA28RLRP?

The MPSA28RLRP has a maximum collector-emitter voltage (V_(BR)CES) rating of 80 V DC, tested at I_C = 100 µA with base open. This rating ensures safe operation in 24 V and 48 V industrial control circuits, provided proper derating is applied above 25°C ambient temperature. The MPSA28RLRP must not be operated beyond this limit to avoid avalanche breakdown or permanent damage.

Is the MPSA28RLRP pin-compatible with the MPSA29RLRP?

Yes, the MPSA28RLRP is pin-compatible with the MPSA29RLRP - both use identical TO-92 package (Case 29-11) with Emitter-Base-Collector pinout (pin 1–3). However, the MPSA29RLRP supports 100 V V_CE, so substitution requires verification that the higher voltage rating is unnecessary for the target circuit. No PCB changes are needed for direct replacement in existing layouts.

What is the typical DC current gain (h_FE) of the MPSA28RLRP at 10 mA collector current?

The MPSA28RLRP specifies a minimum h_FE of 10,000 at I_C = 10 mA and V_CE = 5.0 V, with no upper limit given. Typical performance aligns closely with this minimum in production lots, enabling robust low-base-drive switching. This gain value is confirmed in the official onsemi datasheet MPSA28/D Rev. 2 and applies directly to the MPSA28RLRP variant.

Does the MPSA28RLRP have built-in protection diodes?

No, the MPSA28RLRP does not include built-in flyback or clamp diodes. As a discrete Darlington transistor, it requires external suppression components (e.g., a 1N400x diode across inductive loads) to manage back-EMF during turn-off. This differs from integrated arrays like ULN2003A, which embed clamping diodes - a key distinction when selecting the MPSA28RLRP for relay or solenoid driving.

What is the thermal resistance junction-to-ambient (R_JA) for the MPSA28RLRP in free-air conditions?

The MPSA28RLRP has a specified thermal resistance of R_JA = 200°C/W under standard free-air test conditions (T_A = 25°C, no heatsink). This means each watt of dissipated power raises the junction temperature by 200°C above ambient. At its 625 mW maximum rating, junction temperature rise is ~125°C - confirming why derating is mandatory above 25°C ambient to stay within the −55°C to +150°C operating range.