onsemi MPSA63_D75Z

Overview

MPSA63_D75Z from ON Semiconductor is a PNP Darlington transistor optimized for high-current-switching applications, featuring minimum DC current gain (h_FE) of 5,000 at −10 mA, −5 V, collector-emitter breakdown voltage (V_CE(BR)S) of −30 V, continuous collector current (I_C) of −1.2 A, and TO-92 package with E-B-C pinout - used in relay drivers, lamp dimmers, and low-frequency power switching circuits.

For engineers reviewing the MPSA63_D75Z datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal limits, junction-to-ambient thermal resistance (200 °C/W), saturation voltage behavior (V_CE(sat) ≤ −1.5 V at −100 mA/−0.1 mA), and real-world use context for industrial control and analog signal conditioning designs.

Technical Context

This device implements a monolithic PNP Darlington pair structure with integrated base-emitter resistor network absent - requiring external base drive control. Its high h_FE enables microampere-level base current to switch >1 A collector load, while V_BE(on) of −2.0 V at −100 mA reflects dual-junction forward drop inherent to Darlington topology.

Thermal design relies on FR-4 PCB mounting (1.6″ × 1.6″ × 0.06″) with R_θJA = 200 °C/W; maximum junction temperature is limited to +150 °C, and safe operating area (SOA) is constrained by pulsed duty cycle and ambient temperature per Figure 7.

Key Specifications

Pinout & Package

Package: TO-92 plastic through-hole package with molded epoxy body, lead-free finish, and standard 0.1″ lead pitch. Mounting requires mechanical stability for thermal dissipation; no heatsink pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA63_D75Z, MPSA64 offers complementary NPN functionality but demands topology changes, while PZTA63 provides identical electrical behavior in a thermally superior SMT package - making it ideal for volume production where layout flexibility and thermal headroom are prioritized over through-hole serviceability.

Availability

MPSA63_D75Z is available at Aetrix Electronics and suitable for relay drivers, lamp dimmers, DC motor speed control, and industrial sensor signal conditioning requiring stable component supply across long-lifecycle industrial programs.

Supply support for MPSA63_D75Z 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

ON Semiconductor is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud computing, and consumer markets.

The MPSA63_D75Z belongs to ON Semiconductor's legacy discrete transistor portfolio inherited from Fairchild Semiconductor, engineered for cost-sensitive, high-reliability linear and switching applications in industrial control and power interface circuits.

FAQ

What is the maximum continuous collector current rating for MPSA63_D75Z?

The MPSA63_D75Z is rated for −1.2 A continuous collector current (I_C) at T_A = 25 °C with derating above that temperature. This rating assumes operation within its SOA limits and proper PCB thermal management - specifically a 1.6″ × 1.6″ FR-4 board. At elevated ambient temperatures, power dissipation must be reduced per the 5.0 mW/°C derating curve specified in the datasheet. The MPSA63_D75Z maintains this current capability without forced air or heatsinking under typical industrial ambient conditions.

Does MPSA63_D75Z include an internal base-emitter resistor?

No, the MPSA63_D75Z does not integrate any base-emitter resistor. It is a bare PNP Darlington transistor requiring external base current limiting - typically via a series resistor between the driving source and the base terminal. This distinguishes it from digital transistors (e.g., NSM1012MR) and allows full design flexibility in setting bias points and switching thresholds. The MPSA63_D75Z datasheet confirms this in the "Features" section and electrical test conditions, which specify base current (I_B) explicitly rather than assuming built-in bias networks.

What is the collector-emitter saturation voltage (V_CE(sat)) of MPSA63_D75Z under typical operating conditions?

The MPSA63_D75Z exhibits V_CE(sat) ≤ −1.5 V when operated at I_C = −100 mA and I_B = −0.1 mA, per the Electrical Characteristics table. This value represents worst-case conduction loss during full saturation and remains stable across −40 °C to +125 °C junction temperature, as shown in Figure 2. Designers should use this figure to calculate power dissipation (P = |V_CE(sat) × I_C|) and verify thermal compliance. The MPSA63_D75Z achieves this low saturation voltage due to its Darlington structure's cascaded gain, reducing required base drive while maintaining voltage headroom.

Can MPSA63_D75Z be used in high-frequency switching applications?

The MPSA63_D75Z has an f_T of 125 MHz, but this parameter applies only under small-signal, linear conditions (I_C = −10 mA, V_CE = −5 V). Its Darlington structure introduces significant storage time and slow turn-off characteristics, making it unsuitable for >100 kHz switching. Pulse-width modulation above 20 kHz will suffer from excessive switching losses and incomplete turn-off due to minority carrier lifetime. For high-frequency applications, consider dedicated RF transistors or MOSFETs. The MPSA63_D75Z is intended for DC, audio, and low-frequency (<1 kHz) power switching - confirmed by its typical performance curves and application notes.

How does the thermal resistance R_θJA of MPSA63_D75Z affect PCB layout decisions?

The MPSA63_D75Z specifies R_θJA = 200 °C/W when mounted on a standard 1.6″ × 1.6″ × 0.06″ FR-4 PCB - meaning each watt of dissipated power raises junction temperature by 200 °C above ambient. To maintain T_J ≤ 150 °C at 70 °C ambient, maximum allowable power is just 400 mW. Layout must therefore avoid narrow traces, minimize copper isolation around the collector pad, and consider thermal vias if higher dissipation is needed. The MPSA63_D75Z datasheet explicitly ties R_θJA to this board size, so deviations require re-evaluation using thermal simulation or empirical testing.