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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi MPSA18_D75Z

Name: MPSA18_D75Z
Brand: onsemi
SKU: MPSA18_D75Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MPSA18_D75Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: MPSA18_D75Z.pdf

Description:: TRANS NPN 45V 0.1A TO-92-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MPSA18_D75Z from Fairchild Semiconductor is an NPN general-purpose amplifier optimized for low-noise, high-gain operation at collector currents from 1 µA to 50 mA. It features V_CEO = 45 V, h_FE = 500–1500 (at I_C = 1–10 mA), f_T = 100 MHz, NF = 1.5 dB, and TO-92 package. It is used in preamplifier stages of audio signal chains and sensor interface circuits.

For engineers reviewing the MPSA18_D75Z datasheet, pinout, applications, or equivalent options, this page provides verified electrical parameters, thermal limits, noise performance, packaging configuration (D75Z ammo pack with collector-first orientation), and validated alternatives for low-noise analog amplification design.

Technical Context

The MPSA18_D75Z implements a silicon planar epitaxial NPN structure optimized for stable DC current gain across microampere to milliampere bias ranges. Its 100 MHz f_T and 1.5 dB noise figure at 1 kHz support wideband, low-noise small-signal amplification in linear mode.

Designed for operation up to +150°C junction temperature, it uses Process 07 and shares core characteristics with the 2N5088. The D75Z variant specifies radial ammo packaging with collector lead exiting first, flat side oriented upward, and adhesive tape on top - distinct from D74Z (emitter-first) and D26Z/D27Z (tape-and-reel) configurations.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum safe collector-emitter voltage before breakdown; enables use in 24–36 V analog supply rails.
h_FE	500–1500 - High DC current gain at I_C = 1–10 mA; supports high-impedance base drive and minimal loading on preceding stages.
f_T	100 MHz - Unity-gain bandwidth; supports stable amplification up to ~10 MHz with gain >10 in common-emitter configuration.
NF	1.5 dB @ 1 kHz - Low noise figure with 10 kΩ source resistance; suitable for microphone preamps and precision sensor front-ends.
P_D	625 mW @ T_A = 25°C - Thermal dissipation limit; derates 5.0 mW/°C above ambient, supporting continuous operation at ≤ 100 mA I_C with heatsinking.
C_cb	3.0 pF - Low collector-base capacitance; minimizes Miller effect and improves high-frequency stability.

Pinout & Package

Package: TO-92 (standard 3-lead plastic case, 0.1977 g/unit). D75Z denotes radial ammo packaging with collector lead exiting first, flat side facing upward, and adhesive tape applied to top surface.

Pin/Terminal	Circuit Role	Design Meaning
E (Emitter)	Current sink terminal	Reference node for bias network; connects to ground or emitter degeneration resistor in common-emitter topology.
B (Base)	Control input	Receives input signal or bias current; high h_FE allows low-current drive from op-amp outputs or resistive dividers.
C (Collector)	Current source output	Delivers amplified output current; connected to load resistor or next stage; requires proper decoupling due to 3.0 pF C_cb.

Key Features

Feature	Design Value
Low-noise amplification	1.5 dB noise figure at 1 kHz with 10 kΩ source impedance - enables high-fidelity audio and precision instrumentation front-ends.
High DC current gain	h_FE ≥ 500 at I_C = 1 mA - reduces base drive requirements and improves input impedance matching.
Wideband response	f_T = 100 MHz - supports stable small-signal gain up to mid-VHF range without external compensation.
Robust thermal rating	T_J = –55°C to +150°C - ensures reliability in industrial and automotive under-hood environments.

Applications

Audio Preamplifier Stage	Sensor Signal Conditioning
Use Scenario: Amplifying weak signals from dynamic microphones or piezoelectric sensors before ADC sampling. IC Role / Device Role / Timing Role: NPN small-signal amplifier in common-emitter configuration with emitter degeneration. Use Value: 1.5 dB NF and 500+ h_FE preserve signal integrity while enabling single-stage gain ≥ 100 with minimal added noise.	Use Scenario: Boosting low-level outputs from thermistors, strain gauges, or photodiodes in data acquisition modules. IC Role / Device Role / Timing Role: Transimpedance or voltage amplifier in linear active filter or instrumentation amplifier input stage. Use Value: Stable h_FE across 1 µA–10 mA bias range allows precise gain setting and predictable offset behavior over temperature.
RF Detector Bias Amplifier	Industrial Control Interface
Use Scenario: Providing clean, low-noise bias current to Schottky diode RF detectors in 10–100 MHz receivers. IC Role / Device Role / Timing Role: Constant-current source with low output impedance and minimal ripple coupling. Use Value: 45 V V_CEO and 3.0 pF C_cb prevent detector loading and enable stable operation near RF signal paths.	Use Scenario: Level-shifting and buffering analog control voltages (0–10 V) in PLC I/O modules. IC Role / Device Role / Timing Role: Emitter-follower buffer with high input impedance and low output impedance. Use Value: 100 mA I_C rating and 625 mW power dissipation support sustained 10 V/10 mA drive into reactive loads.

Audio Preamplifier Stage

Sensor Signal Conditioning

Use Scenario: Amplifying weak signals from dynamic microphones or piezoelectric sensors before ADC sampling.

IC Role / Device Role / Timing Role: NPN small-signal amplifier in common-emitter configuration with emitter degeneration.

Use Value: 1.5 dB NF and 500+ h_FE preserve signal integrity while enabling single-stage gain ≥ 100 with minimal added noise.

Use Scenario: Boosting low-level outputs from thermistors, strain gauges, or photodiodes in data acquisition modules.

IC Role / Device Role / Timing Role: Transimpedance or voltage amplifier in linear active filter or instrumentation amplifier input stage.

Use Value: Stable h_FE across 1 µA–10 mA bias range allows precise gain setting and predictable offset behavior over temperature.

RF Detector Bias Amplifier

Industrial Control Interface

Use Scenario: Providing clean, low-noise bias current to Schottky diode RF detectors in 10–100 MHz receivers.

IC Role / Device Role / Timing Role: Constant-current source with low output impedance and minimal ripple coupling.

Use Value: 45 V V_CEO and 3.0 pF C_cb prevent detector loading and enable stable operation near RF signal paths.

Use Scenario: Level-shifting and buffering analog control voltages (0–10 V) in PLC I/O modules.

IC Role / Device Role / Timing Role: Emitter-follower buffer with high input impedance and low output impedance.

Use Value: 100 mA I_C rating and 625 mW power dissipation support sustained 10 V/10 mA drive into reactive loads.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
2N5088	Identical electrical specs per Fairchild documentation; same Process 07, same V_CEO, h_FE, f_T, and NF.	No functional difference; used interchangeably in low-noise preamp designs where TO-92 footprint is acceptable.	Select 2N5088 when standard tape-and-reel (D26Z/D27Z) or bulk packaging is preferred over D75Z ammo orientation.
BC549C	Lower V_CEO (30 V), lower f_T (300 MHz but typically 150 MHz in practice), h_FE = 420–800, NF = 2.5 dB.	Higher noise and lower voltage rating limit use to ≤ 15 V supplies and less demanding audio/sensor roles.	Choose BC549C only if cost sensitivity outweighs noise and voltage margin requirements; verify layout compatibility due to different pinout (E-B-C vs E-C-B).

Compared with 2N5088 and BC549C, the MPSA18_D75Z offers identical low-noise performance to 2N5088 but with documented D75Z packaging orientation for automated radial insertion, while outperforming BC549C in both voltage rating and noise floor - critical for industrial signal conditioning where supply headroom and SNR are constrained.

Availability

MPSA18_D75Z is available at Aetrix Electronics and suitable for audio preamplifiers, sensor signal conditioners, RF detector bias circuits, and industrial control interfaces requiring stable component supply and consistent TO-92 mechanical orientation.

Supply support for MPSA18_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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete devices before its acquisition by ON Semiconductor in 2016.

The MPSA18_D75Z belongs to Fairchild's legacy NPN general-purpose amplifier family designed specifically for low-noise, high-gain linear amplification in consumer, industrial, and instrumentation applications.

FAQ

What is the pin configuration of MPSA18_D75Z?

The MPSA18_D75Z uses a TO-92 package with Emitter-Base-Collector (E-B-C) pinout when viewed with flat side facing up and leads pointing downward. In the D75Z ammo pack, the collector lead exits first, and the flat side is oriented upward - confirming standard E-B-C mechanical layout. This matches Fairchild's Figure 1.0 and is distinct from D74Z (emitter-first) orientation.

Does MPSA18_D75Z support operation at elevated temperatures?

Yes, the MPSA18_D75Z is rated for junction temperatures from –55°C to +150°C. Its thermal resistance R_θJA is 200°C/W, and it dissipates up to 625 mW at 25°C ambient, derating by 5.0 mW/°C above that. This makes MPSA18_D75Z suitable for enclosed industrial enclosures or automotive under-dash locations where ambient exceeds 70°C.

How does the noise performance of MPSA18_D75Z compare to other TO-92 NPN transistors?

The MPSA18_D75Z achieves a noise figure of 1.5 dB at 1 kHz with 10 kΩ source resistance - among the lowest in its class. It matches the 2N5088 and outperforms BC549C (2.5 dB) and PN2222A (5–10 dB). This low-noise capability is confirmed in Fairchild's "Electrical Characteristics" table and is directly attributable to its Process 07 epitaxial structure and optimized doping profile.

Is MPSA18_D75Z suitable for switching applications?

The MPSA18_D75Z is optimized for linear amplification, not switching. While it can saturate (V_CE(sat) = 0.2 V at I_C = 10 mA), its relatively high C_eb (6.5 pF) and lack of specified switching times make it less ideal than dedicated switching transistors like the 2N2222A. For switching, prefer devices with faster t_on/t_off and lower storage time - the MPSA18_D75Z should be used only in analog gain stages.

What does the 'D75Z' suffix indicate for MPSA18_D75Z?

The 'D75Z' suffix identifies the packaging format: radial ammo pack with collector lead exiting first, flat side oriented upward, and adhesive tape applied to the top surface. It is not a device variant - electrical specs match the base MPSA18. D75Z ensures consistent mechanical orientation for automated placement and distinguishes it from D26Z (tape-and-reel, emitter-first) and D74Z (ammo, emitter-first) variants.

MPSA18_D75Z Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Packaging:: Tape & Box (TB)

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 100 mA

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 5mA, 50mA

Current - Collector Cutoff (Max):: 50nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 500 @ 10mA, 5V

Power - Max:: 625 mW

Frequency - Transition:: 100MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

MPSA18_D75Z FAQ

1.How can I place an order for MPSA18_D75Z through Aetrix?

Please submit a Request for Quotation (RFQ) for MPSA18_D75Z on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for MPSA18_D75Z reliable?

The price and inventory of MPSA18_D75Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPSA18_D75Z is usually 5 days.

3.What payment methods are accepted for MPSA18_D75Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPSA18_D75Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPSA18_D75Z?

MPSA18_D75Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPSA18_D75Z order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for MPSA18_D75Z?

For technical support, including MPSA18_D75Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPSA18_D75Z requirements.

6.How does Aetrix verify that MPSA18_D75Z is sourced from the original manufacturer or authorized distributors?

All MPSA18_D75Z products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MPSA18_D75Z meets industry standards.

7.What is the process for return or replacement of MPSA18_D75Z?

All MPSA18_D75Z units undergo pre-shipment inspection (PSI). If there is an issue with MPSA18_D75Z, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The MPSA18_D75Z part is unused and in its original packaging.

Return procedure for MPSA18_D75Z:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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