onsemi MPSA75RLRP

Overview

MPSA75RLRP from onsemi is a PNP silicon Darlington transistor in TO-92 package, rated for −40 V V_CE, −500 mA I_C, and 625 mW power dissipation at 25°C, with DC current gain h_FE ≥ 10,000 at −10 mA/−5 V, used in low-speed switching and interface driver circuits for industrial control and relay drivers.

For engineers reviewing the MPSA75RLRP datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed high h_FE, low V_CE(sat) ≤ −1.5 V at −100 mA/−0.1 mA drive, Pb-free TO-92 packaging, and thermal resistance R_JA = 200°C/W for ambient-limited linear operation.

Technical Context

The MPSA75RLRP integrates two cascaded PNP transistors in a single TO-92 package to achieve ultra-high DC current gain (≥10,000), enabling microampere-level base drive to switch 100+ mA loads. Its Darlington configuration inherently increases V_BE(on) to −2.0 V and limits f_T to 1.25–2.4 MHz, making it unsuitable for RF or high-frequency switching.

It operates within −55°C to +150°C junction temperature range and exhibits low leakage: I_CBO ≤ −100 nA at −30 V and I_CES ≤ −500 nA at −30 V, supporting stable biasing in low-power analog and digital interface applications where leakage-sensitive turn-off is required.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-11, Style 1), 3-lead through-hole plastic package with standard lead spacing and E-B-C pin assignment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA75RLRP, the MPSA75RLRAG provides identical performance with certified Pb-free construction, while the MPSA77RLRP trades no gain or speed improvement for higher voltage tolerance-making MPSA75RLRP optimal for cost-constrained 24 V industrial switching where its −40 V rating suffices.

Availability

MPSA75RLRP is available at Aetrix Electronics and suitable for industrial control, relay driving, and legacy microcontroller interface applications requiring stable component supply and long-term obsolescence management.

Supply support for MPSA75RLRP 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, intelligent power and sensing solutions for automotive, industrial, cloud, and consumer markets.

The MPSA75RLRP belongs to onsemi's general-purpose bipolar transistor product line, designed specifically for cost-sensitive, medium-current linear and switching applications in industrial and legacy electronic systems.

FAQ

What is the maximum collector-emitter voltage rating for the MPSA75RLRP?

The MPSA75RLRP has a maximum collector-emitter voltage (V_CE) rating of −40 V DC. This value is specified under test conditions of I_C = −100 µA and V_BE = 0 V. Exceeding this voltage risks avalanche breakdown and permanent device damage. Designers should maintain at least 20% derating margin in 24 V systems, confirming that transient spikes remain below −32 V in actual circuit operation. The MPSA75RLRP is not rated for 48 V bus applications-those require the MPSA77RLRP variant.

Does the MPSA75RLRP include an integrated base resistor?

No, the MPSA75RLRP does not include an integrated base resistor. It is a bare Darlington transistor requiring external biasing components. Unlike digital transistors (e.g., NSM1012MR), the MPSA75RLRP relies on externally calculated base resistors to set I_B for desired I_C and saturation. Typical design uses a series resistor from MCU GPIO to Pin 2 (Base), with emitter tied to V_CC and collector driving the load to ground. The MPSA75RLRP's lack of internal resistor preserves flexibility across varying supply voltages and drive strengths.

What is the thermal resistance (R_JA) of the MPSA75RLRP and how does it affect layout?

The MPSA75RLRP has a junction-to-ambient thermal resistance (R_JA) of 200°C/W, measured in free-air conditions per JEDEC JESD51-2. This means each watt of dissipated power raises the junction temperature by 200°C above ambient. At its 625 mW maximum rating, even at 25°C ambient, junction temperature reaches 150°C-its absolute limit. To ensure reliability, PCB layout must avoid enclosing the TO-92 body, minimize copper isolation around leads, and consider forced airflow or thermal vias if power exceeds 300 mW. The MPSA75RLRP's R_JA confirms it is intended for intermittent or low-duty-cycle operation-not continuous high-power use.

Can the MPSA75RLRP be used as a direct replacement for the MPSA75RLRA?

Yes, the MPSA75RLRP can replace the MPSA75RLRA in most applications because both share identical die, electrical specifications, and TO-92 package. The only difference is packaging format: MPSA75RLRP ships in 2,000-unit ammo packs, while MPSA75RLRA uses tape-and-reel. No PCB or schematic changes are needed. However, automated pick-and-place equipment may require different feeder setup due to carrier type. For manual assembly or low-volume prototyping, the MPSA75RLRP performs identically to the MPSA75RLRA-and both are functionally equivalent to the MPSA75RLRAG except for Pb-free compliance.

What is the typical DC current gain (h_FE) of the MPSA75RLRP and at what conditions is it guaranteed?

onsemi guarantees a minimum DC current gain (h_FE) of 10,000 for the MPSA75RLRP at I_C = −10 mA and V_CE = −5.0 V, with typical values reaching up to 25,000 under those conditions. This specification is validated per the official datasheet (MPSA75/D, Rev. 4). Gain drops significantly at higher currents (e.g., ~5,000 at −100 mA) and lower V_CE. Because h_FE varies with temperature and operating point, designs using the MPSA75RLRP must verify gain stability across the full expected I_C/V_CE range-not rely solely on the −10 mA/−5 V guarantee. The MPSA75RLRP's high h_FE remains its defining advantage for low-base-drive applications.