NXP Semiconductors MPSA92,126

Overview

MPSA92,126 from NXP Semiconductors is a PNP high-voltage bipolar junction transistor in TO-92 (SOT54) package, rated for −300 V V_CEO and −300 V V_CBO, with DC current gain h_FE ≥ 40 at I_C = −10 mA and V_CE = −10 V, used in high-voltage switching circuits such as CRT flyback drivers and relay interface stages.

For engineers reviewing the MPSA92,126 datasheet, MPSA92,126 pinout, MPSA92,126 application, or MPSA92,126 equivalent, key selection criteria include verified −300 V breakdown rating, TO-92 mechanical compatibility, low leakage (I_CBO ≤ −250 nA), saturation voltage under defined drive conditions, and confirmed PNP polarity for high-side switching topologies.

Technical Context

This PNP transistor operates with reverse-biased collector-base and emitter-base junctions up to −300 V and −5 V respectively, supporting high-voltage off-state blocking. Its f_T of 50 MHz enables use in moderate-frequency switching above audio range while maintaining stable DC gain across I_C = −1 mA to −30 mA.

Thermal resistance R_{th j-a} is 200 K/W when mounted on FR4 PCB, limiting continuous power dissipation to 625 mW at T_amb ≤ 25 °C. Saturation voltages V_CEsat ≤ −500 mV and V_BEsat ≤ −900 mV are specified at I_C = −20 mA / I_B = −2 mA, confirming usable gain under forced-beta switching conditions.

Key Specifications

Pinout & Package

Package: TO-92 (SOT54), plastic single-ended leaded through-hole package with 3 leads; outline conforms to IEC/JEDEC SC-43A standard; body dimensions: L = 14.5 mm, D = 4.8 mm, E = 4.2 mm, e = 2.54 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP high-voltage transistor applications.

Compared with MPSA92,126, MPSA42,126 offers matched voltage capability but inverted polarity-requiring full circuit redesign-while BC639-16 trades critical −300 V rating for higher current and gain at the cost of HV suitability.

Availability

MPSA92,126 is available at Aetrix Electronics and suitable for CRT deflection circuits, industrial relay interfaces, high-voltage signal amplifiers, and legacy power supply protection requiring stable component supply and long-lifecycle support.

Supply support for MPSA92,126 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, delivering high-performance analog, logic, and power devices for automotive, industrial, and consumer applications.

The MPSA92,126 belongs to NXP's discrete bipolar transistor product line, designed specifically for high-voltage switching and amplification in legacy and maintenance-critical systems where reliability and long-term availability are essential.

FAQ

What is the maximum collector-emitter voltage rating for MPSA92,126?

The MPSA92,126 has a maximum collector-emitter voltage (V_CEO) rating of −300 V with the base open, as confirmed in the NXP product data sheet. This rating applies under steady-state DC conditions and defines the upper limit for safe off-state blocking in high-voltage switching applications. Exceeding this voltage risks permanent junction breakdown.

Is MPSA92,126 pin-compatible with other TO-92 PNP transistors like BC557?

No, MPSA92,126 is not pin-compatible with BC557. While both use TO-92 packages, BC557 has emitter-base-collector (E-B-C) pinout (1–2–3), whereas MPSA92,126 uses collector-base-emitter (C-B-E) pinout (1–2–3). Swapping them without verifying pin assignment will cause circuit malfunction or damage.

What is the typical DC current gain (h_FE) of MPSA92,126 at 10 mA collector current?

The typical DC current gain (h_FE) of MPSA92,126 is ≥40 at I_C = −10 mA and V_CE = −10 V, per the NXP datasheet. This value is guaranteed minimum under those exact test conditions and supports robust base drive design for switching loads up to 100 mA without gain collapse.

Can MPSA92,126 be used in place of MPSA42,126?

No, MPSA92,126 cannot directly replace MPSA42,126 because they are complementary types: MPSA92,126 is PNP and MPSA42,126 is NPN. Their polarities, biasing requirements, and circuit roles are inverted. Substitution would require complete schematic revision and layout changes to accommodate opposite current flow and voltage referencing.

What thermal resistance does MPSA92,126 exhibit when mounted on a standard FR4 PCB?

MPSA92,126 exhibits a junction-to-ambient thermal resistance (R_{th j-a}) of 200 K/W when mounted on a standard FR4 printed-circuit board, as specified in the NXP datasheet. This value assumes no added heatsinking and defines the thermal derating curve: power dissipation must be reduced by 6.25 mW per °C rise above 25 °C ambient.