Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

onsemi KSA1174PBU

Name: KSA1174PBU
Brand: onsemi
SKU: KSA1174PBU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: KSA1174PBU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 Short Body

Datasheet:: KSA1174PBU.pdf

Description:: TRANS PNP 120V 0.05A TO-92S

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:6,471

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

KSA1174PBU from Fairchild Semiconductor is a PNP epitaxial silicon transistor designed for audio-frequency low-noise amplification, with V_CEO = −120 V, I_C = −50 mA, P_C = 300 mW, hFE₂ = 200–400, and f_T = 50–100 MHz. It serves as the complementary device to KSC2784 in push-pull amplifier stages.

For engineers reviewing the KSA1174PBU datasheet, pinout, applications, or equivalent options, key selection criteria include its low-noise performance (NV = 25–40 mV), high DC current gain at low collector current, TO-92S package footprint, and suitability for linear audio preamplifier and driver stages requiring stable hFE and low V_CE(sat).

Technical Context

The KSA1174PBU operates as a general-purpose PNP bipolar junction transistor optimized for low-noise analog amplification in the audio band. Its design emphasizes high hFE uniformity across the 200–400 range (hFE₂ classification 'P'), low base-emitter on-voltage (−0.55 to −0.65 V at I_C = −1 mA), and tight Cob control (2–3 pF at V_CB = −30 V).

It features a maximum junction temperature of 150°C and power derating above 25°C ambient, with guaranteed ICEO ≤ −1 µA at V_CE = −100 V and ICBO ≤ −50 nA at V_CB = −120 V - confirming robust cutoff behavior for bias-stable amplifier designs.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−120 V: Supports high-voltage audio rails up to ±60 V supply without breakdown.
I_C	−50 mA: Sufficient for line-level and low-power driver stage collector current handling.
hFE₂	200–400: Tight DC current gain bin ensures predictable bias point stability in discrete gain blocks.
f_T	50–100 MHz: Enables faithful amplification through full audio spectrum (20 Hz–20 kHz) with margin.
V_CE(sat)	−0.09 to −0.3 V at I_C = −10 mA / I_B = −1 mA: Minimizes voltage drop and power loss in saturated switching or Class-A bias.
NV	25–40 mV: Low inherent noise supports high-SNR preamplifier front-ends in sensitive audio paths.
C_ob	2–3 pF at V_CB = −30 V: Limits Miller capacitance impact on high-frequency gain roll-off.

Pinout & Package

Package: TO-92S - 3-lead plastic through-hole package with 1.27 mm lead pitch, 3.72 mm body width, and 4.00 mm height; optimized for manual assembly and compact PCB layouts.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current source terminal for PNP operation	Connected to most positive rail in common-emitter amplifier; defines reference for base bias network.
2 (Collector)	Current sink terminal	Typically tied to load resistor or active load; output node for voltage amplification stage.
3 (Base)	Control input for minority-carrier injection	Receives bias current to set operating point; requires stable, low-impedance drive for low-noise performance.

Key Features

Feature	Design Value
Low-noise audio amplification	NV = 25–40 mV enables use in microphone preamps and phono stages where signal integrity is critical.
Complementary pairing with KSC2784	Matched V_CEO, hFE range, and package allow symmetrical push-pull output stages without thermal drift mismatch.
High hFE₂ binning (P-class)	Guaranteed 200–400 hFE at I_C = −1 mA ensures consistent gain and bias across production lots.
Low V_CE(sat) at moderate current	−0.09 V typical at I_C/I_B = 10 enables efficient Class-A operation with minimal quiescent power dissipation.

Applications

Audio Preamp Stage	Push-Pull Output Driver
Use Scenario: Amplifying low-level signals from dynamic microphones or magnetic phono cartridges before ADC or power amplification. IC Role / Device Role / Timing Role: Discrete PNP transistor configured in common-emitter topology for voltage gain and impedance transformation. Use Value: Low NV and high hFE ensure >80 dB SNR and stable DC operating point over temperature in single-supply designs.	Use Scenario: Driving low-impedance headphones or small loudspeakers in Class-B or AB configurations. IC Role / Device Role / Timing Role: Complementary PNP half of push-pull pair, matched to NPN KSC2784 for symmetrical swing and crossover distortion reduction. Use Value: Tight hFE₂ binning and identical TO-92S thermal profile minimize thermal tracking mismatch and DC offset drift.
Instrumentation Signal Conditioning	DC-Coupled Line Driver
Use Scenario: Buffering and gain-setting in precision analog sensor interfaces (e.g., thermocouple amplifiers) requiring low input bias current. IC Role / Device Role / Timing Role: Emitter-follower buffer or differential pair active load with high input impedance and low output impedance. Use Value: ICEO ≤ −1 µA and ICBO ≤ −50 nA ensure negligible leakage-induced offset in high-gain, DC-coupled topologies.	Use Scenario: Transmitting balanced or unbalanced line-level signals over short cables (<2 m) with minimal distortion. IC Role / Device Role / Timing Role: Common-collector (emitter-follower) stage providing low-Z output and unity voltage gain. Use Value: V_CE(sat) ≤ −0.3 V and f_T ≥ 50 MHz preserve transient fidelity and slew rate for music-grade line drivers.

Audio Preamp Stage

Push-Pull Output Driver

Use Scenario: Amplifying low-level signals from dynamic microphones or magnetic phono cartridges before ADC or power amplification.

IC Role / Device Role / Timing Role: Discrete PNP transistor configured in common-emitter topology for voltage gain and impedance transformation.

Use Value: Low NV and high hFE ensure >80 dB SNR and stable DC operating point over temperature in single-supply designs.

Use Scenario: Driving low-impedance headphones or small loudspeakers in Class-B or AB configurations.

IC Role / Device Role / Timing Role: Complementary PNP half of push-pull pair, matched to NPN KSC2784 for symmetrical swing and crossover distortion reduction.

Use Value: Tight hFE₂ binning and identical TO-92S thermal profile minimize thermal tracking mismatch and DC offset drift.

Instrumentation Signal Conditioning

DC-Coupled Line Driver

Use Scenario: Buffering and gain-setting in precision analog sensor interfaces (e.g., thermocouple amplifiers) requiring low input bias current.

IC Role / Device Role / Timing Role: Emitter-follower buffer or differential pair active load with high input impedance and low output impedance.

Use Value: ICEO ≤ −1 µA and ICBO ≤ −50 nA ensure negligible leakage-induced offset in high-gain, DC-coupled topologies.

Use Scenario: Transmitting balanced or unbalanced line-level signals over short cables (<2 m) with minimal distortion.

IC Role / Device Role / Timing Role: Common-collector (emitter-follower) stage providing low-Z output and unity voltage gain.

Use Value: V_CE(sat) ≤ −0.3 V and f_T ≥ 50 MHz preserve transient fidelity and slew rate for music-grade line drivers.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP low-noise amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MPSA92	V_CEO = −300 V, hFE = 50–250 (unbinned), f_T ≈ 50 MHz, TO-92 package	Higher breakdown but wider hFE spread; less suitable for matched pair designs	Preferred when higher voltage margin is required and hFE matching is not critical
KSA992	V_CEO = −160 V, hFE₂ = 200–400 (same bin), f_T = 80 MHz, TO-92S package	Near-identical pinout and gain bin; higher f_T and breakdown support extended bandwidth	Drop-in upgrade path if higher speed or voltage headroom is needed without layout change

Compared with MPSA92 and KSA992, the KSA1174PBU offers tighter hFE consistency and lower noise in its designated audio band, while KSA992 provides enhanced frequency response and voltage rating within the same TO-92S footprint - making it the only true functional upgrade option without board revision.

Availability

KSA1174PBU is available at Aetrix Electronics and suitable for audio preamplifiers, push-pull output drivers, and instrumentation signal conditioning requiring stable component supply and long-term obsolescence management.

Supply support for KSA1174PBU 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 components before its acquisition by ON Semiconductor in 2016.

The KSA1174PBU belongs to Fairchild's legacy audio transistor family, engineered specifically for low-noise, high-linearity analog signal amplification in consumer and professional audio equipment.

FAQ

What is the pin configuration of the KSA1174PBU?

The KSA1174PBU uses a TO-92S package with standard pinout: Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base. This matches JEDEC TO-92S mechanical specification and is verified in Fairchild's Rev. A2 datasheet Figure "Package Dimensions". The KSA1174PBU must be mounted with correct orientation to maintain proper PNP biasing in circuit.

Is the KSA1174PBU suitable for surface-mount assembly?

No, the KSA1174PBU is a through-hole device in TO-92S package and is not designed for SMT reflow. Its lead form, pitch (1.27 mm), and body dimensions require wave soldering or hand soldering. For SMT alternatives, consider the SOT-23 variant KSA1174Y, which shares electrical specs but differs in footprint and thermal performance.

What does the 'P' suffix in KSA1174PBU indicate?

Per Fairchild's datasheet Rev. A2, the 'P' in KSA1174PBU denotes hFE₂ classification - specifying a DC current gain range of 200–400 at V_CE = −6 V and I_C = −1 mA. The 'BU' suffix indicates tape-and-reel packaging per JEDEC standards. The KSA1174PBU is thus a binned, production-ready version optimized for gain-critical audio applications.

How does the KSA1174PBU compare to the KSC2784 in circuit design?

The KSA1174PBU is the PNP complement to the NPN KSC2784: both share identical V_CEO (−120 V), I_C (−50 mA / +50 mA), P_C (300 mW), and TO-92S package. Their matched hFE bins and thermal profiles enable symmetrical push-pull stages. In practice, the KSA1174PBU handles the upper half of the signal swing while KSC2784 handles the lower half - minimizing crossover distortion in Class-AB amplifiers.

Can the KSA1174PBU be used in switching applications?

The KSA1174PBU is characterized and optimized for linear amplification, not switching. While it can saturate (V_CE(sat) = −0.09 V), its f_T and Cob are tuned for analog bandwidth, not fast turn-off. Switching use may result in excessive storage time and inconsistent duty-cycle control. For dedicated switching, Fairchild's FMMT617 or similar PNP switches are better suited than the KSA1174PBU.

KSA1174PBU Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Short Body

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 50 mA

Voltage - Collector Emitter Breakdown (Max):: 120 V

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 1mA, 10mA

Current - Collector Cutoff (Max):: 1µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 200 @ 1mA, 6V

Power - Max:: 300 mW

Frequency - Transition:: 100MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92S

KSA1174PBU FAQ

1.How can I place an order for KSA1174PBU through Aetrix?

Please submit a Request for Quotation (RFQ) for KSA1174PBU 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 KSA1174PBU reliable?

The price and inventory of KSA1174PBU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSA1174PBU is usually 5 days.

3.What payment methods are accepted for KSA1174PBU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSA1174PBU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSA1174PBU?

KSA1174PBU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSA1174PBU 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 KSA1174PBU?

For technical support, including KSA1174PBU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSA1174PBU requirements.

6.How does Aetrix verify that KSA1174PBU is sourced from the original manufacturer or authorized distributors?

All KSA1174PBU 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 KSA1174PBU meets industry standards.

7.What is the process for return or replacement of KSA1174PBU?

All KSA1174PBU units undergo pre-shipment inspection (PSI). If there is an issue with KSA1174PBU, 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 KSA1174PBU part is unused and in its original packaging.

Return procedure for KSA1174PBU:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…