onsemi KSA992PBU

Overview

KSA992PBU from onsemi is a PNP epitaxial silicon transistor designed for audio-frequency low-noise amplification, with −120 V V_CEO, −50 mA I_C, 500 mW power dissipation, and 50–100 MHz f_T, commonly used in preamplifier stages of consumer audio equipment.

For engineers reviewing the KSA992PBU datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 package, h_FE classification (FB: 430–600), low noise figure (7 dB at 1 kHz), and complementary pairing with KSC1845 in push-pull amplifier designs.

Technical Context

This device operates as a general-purpose PNP bipolar junction transistor optimized for low-noise analog signal amplification in the audio band. Its −120 V breakdown ratings and 150 °C junction temperature support robust operation in linear bias configurations.

The KSA992PBU exhibits h_FE = 300–600 at I_C = −1 mA and V_CE = −6 V, V_CE(sat) ≤ −0.30 V at I_C = −10 mA/I_B = −1 mA, and Cob = 2–3 pF at V_CB = −30 V, enabling stable gain and minimal capacitive loading in high-impedance node applications.

Key Specifications

Pinout & Package

Package: TO-92 (Case 135AN), 4.83 mm × 4.76 mm body, lead-formed, Pb-free, through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP small-signal amplifier applications.

Compared with KSA992FBU and MPSA92, the KSA992PBU shares full electrical equivalence with KSA992FBU but is discontinued; MPSA92 trades low-noise linearity for higher voltage tolerance, making it less suitable for precision audio gain stages where h_FE consistency and noise floor matter.

Availability

KSA992PBU is available at Aetrix Electronics and suitable for phono preamplifiers, headphone driver circuits, and industrial sensor signal conditioning requiring stable component supply and legacy design continuity.

Supply support for KSA992PBU 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, and intelligent edge applications.

The KSA992PBU belongs to onsemi's legacy discrete transistor product line, engineered specifically for high-fidelity audio signal amplification and complementary analog circuit design.

FAQ

What is the package type and pin configuration of the KSA992PBU?

The KSA992PBU uses a TO-92 package (Case 135AN) with standard pinout: Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base. This configuration is verified in the official onsemi datasheet and matches mechanical drawings dated July 2016. The device is lead-formed and Pb-free, intended for through-hole PCB assembly. KSA992PBU maintains identical pinout and footprint compatibility with other TO-92 PNP transistors like KSA992FBU and MPSA92.

Is the KSA992PBU still in active production?

No-the KSA992PBU is marked as discontinued in Revision 5 of the onsemi datasheet (January 2026). It has been superseded by KSA992FBU, which shares identical electrical specifications and TO-92 packaging but is supplied in bulk bags (10,000 units). Aetrix Electronics maintains limited legacy stock of KSA992PBU for design continuity, but recommends KSA992FBU for all new designs.

What is the hFE classification for the KSA992PBU, and how does it affect circuit design?

The KSA992PBU carries the FB h_FE classification, guaranteeing a DC current gain range of 430–600 at I_C = −1 mA and V_CE = −6 V. This tight binning simplifies bias network calculation, improves channel matching in stereo amplifiers, and reduces unit-to-unit variation in gain and quiescent current-critical for low-distortion audio applications. KSA992PBU's FB grade is explicitly documented in the "hFE CLASSIFICATION" table on page 2 of the datasheet.

How does the noise performance of the KSA992PBU compare to other PNP transistors?

The KSA992PBU delivers a noise figure of 7 dB at V_CE = −5 V, I_C = −1.0 mA, R_S = 100 kΩ, and f = 1 kHz-measured and specified in the Electrical Characteristics table. This outperforms generic PNP transistors like MPSA92 (NF not specified) and aligns with its "Audio Frequency Low-Noise Amplifier" feature designation. For low-noise preamp stages, this value directly enables higher signal-to-noise ratio without requiring additional filtering or feedback compensation in the KSA992PBU design.

Can the KSA992PBU be used as a direct replacement for the KSC1845 in a circuit?

No-the KSA992PBU is a PNP transistor, while the KSC1845 is an NPN device; they are complementary, not interchangeable. The datasheet explicitly states "Complement to KSC1845", meaning they are intended for paired use in push-pull or differential configurations-not substitution. Replacing KSC1845 with KSA992PBU would reverse polarity and disable circuit operation. Always verify polarity, pinout, and biasing when selecting replacements for KSA992PBU or KSC1845.