onsemi MPSA29_D75Z

Overview

MPSA29_D75Z from onsemi is an NPN silicon Darlington transistor in TO-92 package, rated for 100 V_CEO, 500 mA continuous collector current, and 1.5 W power dissipation at T_C = 25°C. It delivers DC current gain (h_FE) ≥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 high-gain switching and linear amplification stages of industrial control interfaces.

For engineers reviewing the MPSA29_D75Z datasheet, pinout, applications, or equivalent options, key selection criteria include its 100 V breakdown rating, Darlington architecture enabling low-base-drive sensitivity, thermal resistance (R_θJC = 83.3°C/W), and Pb-free TO-92 packaging compliant with RoHS Directive 2011/65/EU.

Technical Context

The MPSA29_D75Z implements a monolithic NPN Darlington pair with integrated base-emitter resistor network absent - requiring external base biasing. Its high h_FE enables microampere-level input drive while sustaining 100 mA output current, and its f_T ≥125 MHz supports moderate-frequency switching up to ~10 MHz under resistive loads.

Thermal design relies on junction-to-case conduction (R_θJC = 83.3°C/W) rather than ambient convection (R_θJA = 200°C/W), making heatsinking via the collector lead critical above 500 mW dissipation. Safe operating area (SOA) curves confirm second-breakdown immunity up to 100 V × 100 mA at 100 ms pulse width.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-11), straight-lead configuration, Pb-free, 2000 units per ammo pack. Dimensions conform to ANSI Y14.5M–1982; lead pitch = 2.54 mm, body height = 4.45–5.20 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA29_D75Z, MPSA29RLRPG offers identical performance in a certified Pb-free format ideal for new designs, while ULN2003A provides integration benefits at the cost of flexibility and thermal independence - making MPSA29_D75Z optimal for single-load, thermally sensitive, or bias-customized implementations.

Availability

MPSA29_D75Z is available at Aetrix Electronics and suitable for industrial relay drivers, DC motor speed control, LED dimming circuits, and linear voltage regulator pass elements requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MPSA29_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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and IoT applications.

The MPSA29_D75Z belongs to onsemi's Preferred Devices family of general-purpose bipolar transistors engineered for reliability, manufacturability, and broad applicability across industrial control, power management, and interface circuitry.

FAQ

What is the maximum continuous collector current rating for MPSA29_D75Z?

The MPSA29_D75Z is rated for 500 mA continuous collector current (I_C) at T_A = 25°C. Derating applies above 25°C ambient: 5.0 mW/°C for ambient-limited operation, or 12 mW/°C when mounted on a heatsink with case temperature maintained at 25°C. At T_C = 25°C, it supports up to 1.5 W total dissipation - confirming its suitability for sustained 300–400 mA loads in well-ventilated industrial enclosures.

Does MPSA29_D75Z have an integrated base resistor?

No, the MPSA29_D75Z does not include an integrated base resistor. It is a bare Darlington transistor requiring external base biasing - typically via a series resistor from a microcontroller GPIO or op-amp output. This design allows precise control of base current and avoids fixed gain limitations seen in digital transistors like the MMBT2222A, making MPSA29_D75Z appropriate for analog-linear and high-precision switching applications.

What is the safe operating area (SOA) limitation for MPSA29_D75Z at 100 V?

At V_CE = 100 V, the MPSA29_D75Z SOA restricts continuous current to ≤10 mA to avoid second breakdown. Pulse operation extends this: at 100 V, it supports 100 mA for ≤100 ms pulses (duty cycle ≤10%). This behavior is confirmed in Figure 5 of the official datasheet, where the thermal limit intersects the 100 V boundary at ~10 mA DC and rises to 100 mA within the 100 ms second-breakdown limit zone.

Is MPSA29_D75Z RoHS-compliant and halogen-free?

Yes, MPSA29_D75Z is RoHS-compliant and halogen-free. The "G" suffix in its full part number denotes Pb-free construction per JEDEC J-STD-609, and onsemi confirms full compliance with EU Directive 2011/65/EU and IEC 61249-2-21. Material content reports verify bromine and chlorine levels below 900 ppm each, satisfying IPC-4101D requirements for halogen-free printed wiring boards.

How does the f_T of MPSA29_D75Z affect its switching performance?

The MPSA29_D75Z has f_T ≥125 MHz, indicating usable gain up to that frequency. In practice, its Darlington structure introduces storage time delays, limiting practical switching to ≤5 MHz for clean edges. Rise/fall times are ~1.2 µs at I_C = 100 mA with R_B = 10 kΩ - sufficient for relay driving and PWM motor control but unsuitable for RF or >10 MHz digital logic interfacing. For higher-speed needs, a single-stage NPN like the MMBT5551 is recommended instead of MPSA29_D75Z.