onsemi MPSA29-D26Z

Overview

MPSA29-D26Z from onsemi is an NPN silicon Darlington transistor in a 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 low-level signal amplification circuits such as relay drivers and sensor interface stages.

For engineers reviewing the MPSA29-D26Z datasheet, pinout, applications, or equivalent options, key selection criteria include its 100 V breakdown rating, Darlington architecture enabling microampere base drive, thermal resistance of 83.3°C/W (junction-to-case), and Pb-free TO-92 packaging compliant with RoHS requirements.

Technical Context

The MPSA29-D26Z integrates two cascaded NPN transistors in a monolithic Darlington configuration, delivering ultra-high DC current gain while maintaining single-package simplicity. Its structure supports low-base-drive operation in linear and saturated switching modes, with guaranteed V_(BR)CES = 100 V and V_(BR)CBO = 100 V under specified test conditions.

Thermal design is enabled by its 83.3°C/W junction-to-case thermal resistance and 1.5 W maximum power dissipation at case temperature 25°C, derating linearly at 12 mW/°C above that point. The device operates across –55°C to +150°C junction temperature range, supporting industrial and automotive ambient environments when properly heatsinked.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-11), straight-lead, Pb-free, 3-pin through-hole plastic package with standard JEDEC outline and 2.54 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA29-D26Z, MPSA29RLRPG offers identical performance in a different packaging format ideal for SMT line integration, while ULN2003A provides system-level integration benefits - including clamping diodes and resistor networks - at the cost of fixed channel count and less granular thermal management.

Availability

MPSA29-D26Z is available at Aetrix Electronics and suitable for relay driver circuits, low-level sensor amplifiers, LED array drivers, and industrial power supply feedback requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MPSA29-D26Z 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, medical, and IoT applications.

The MPSA29-D26Z belongs to onsemi's Preferred Devices family of general-purpose bipolar transistors, engineered for high reliability, consistent parametric performance, and broad compatibility across industrial control, power management, and signal conditioning applications.

FAQ

What is the maximum collector-emitter voltage rating for MPSA29-D26Z?

The MPSA29-D26Z has a guaranteed minimum collector-emitter breakdown voltage V_(BR)CES of 100 Vdc when I_C = 100 mAdc and V_BE = 0. This rating applies under open-emitter test conditions and defines the absolute maximum voltage the device can block in common-emitter configuration without avalanche conduction. Designers should maintain at least 20% margin below this value for long-term reliability in switching applications.

Does MPSA29-D26Z have a built-in base-emitter resistor?

No, the MPSA29-D26Z does not include any integrated base-emitter resistor. It is a bare Darlington transistor requiring external base current limiting - typically via a series resistor sized to deliver ~0.1 mA base current for 100 mA collector load. Unlike array devices such as ULN2003A, MPSA29-D26Z provides full design flexibility for custom biasing but places responsibility for safe operating area compliance on the circuit designer.

What is the thermal resistance junction-to-case (R_θJC) for MPSA29-D26Z?

The MPSA29-D26Z has a specified thermal resistance R_θJC of 83.3°C/W. This value reflects heat transfer from the silicon die to the TO-92 package case surface under standardized test conditions. When mounted to a copper pour or heatsink, this parameter enables accurate junction temperature estimation using T_J = T_C + (P_D × R_θJC), critical for ensuring operation remains within the –55°C to +150°C allowable junction range.

Can MPSA29-D26Z replace MPSA28 in existing designs?

MPSA29-D26Z can replace MPSA28 in most designs where higher voltage blocking is beneficial, as both share identical pinout, package, and gain characteristics but differ in breakdown ratings: MPSA28 specifies V_CEO = 80 V versus 100 V for MPSA29-D26Z. No layout changes are needed, but designers should verify that the increased voltage margin does not introduce unintended timing or stability effects in linear amplifier configurations due to internal capacitance differences.

Is MPSA29-D26Z RoHS compliant and lead-free?

Yes, MPSA29-D26Z is manufactured in a Pb-free TO-92 package and complies with RoHS Directive 2011/65/EU. The "G" suffix in related part numbers (e.g., MPSA29RLRPG) explicitly denotes Pb-free construction, and the device uses matte tin lead plating with no lead content exceeding 0.1 wt%. Full compliance documentation, including substance declarations and test reports, is available through onsemi's product environmental page.