onsemi KSA1015OTA

Overview

KSA1015OTA from onsemi is a PNP epitaxial silicon transistor designed for low-frequency amplification and switching in analog signal paths, with confirmed parameters: V_CBO = −50 V, I_C = −150 mA, P_D = 400 mW, h_FE = 70–400 (class-dependent), and f_T = 80 MHz - used in audio preamplifier stages and discrete bias networks.

For engineers reviewing the KSA1015OTA datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 package compatibility, complementary pairing with KSC1815, DC gain classification (GR/Y/O), saturation voltage performance at −100 mA, and thermal derating behavior above 25 °C.

Technical Context

This device operates as a general-purpose PNP bipolar junction transistor with fixed emitter-base and collector-base breakdown limits, supporting linear amplification under V_CE ≤ −50 V and I_C ≤ −150 mA. Its h_FE varies by classification (GR: 200–400; Y: 120–240; O: 70–140) and drops to ≥25 at I_C = −150 mA.

It exhibits V_CE(sat) ≤ −0.3 V and V_BE(sat) ≤ −1.1 V at I_C = −100 mA / I_B = −10 mA, with Cob = 4–7 pF at V_CB = −10 V and f_T = 80 MHz - confirming suitability for sub-100 MHz small-signal amplification and switching where low noise (NF = 0.5–6 dB) and stable DC gain are required.

Key Specifications

Pinout & Package

Package: TO-92 (Case 135AR), 3-lead, lead-formed, Pb-free, RoHS-compliant. Dimensions: 4.83 mm × 4.76 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KSA992FTA and MPSA92, the KSA1015OTA provides the best balance of low-noise performance, standardized h_FE grading, and proven reliability in consumer audio and industrial bias circuits - especially where −50 V rating and 400 mW dissipation are sufficient.

Availability

KSA1015OTA is available at Aetrix Electronics and suitable for audio preamplifier stages, discrete bias networks, and LED driver switches requiring stable component supply and long-term BOM continuity.

Supply support for KSA1015OTA 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 specializing in energy-efficient power management, analog, and discrete devices for automotive, industrial, and consumer markets.

The KSA1015OTA belongs to onsemi's legacy general-purpose bipolar transistor family, engineered for reliability and consistency in low-frequency analog signal conditioning and discrete power control applications.

FAQ

What is the maximum collector-emitter voltage rating for KSA1015OTA?

The KSA1015OTA has a guaranteed V_CEO rating of −50 V at T_A = 25 °C. This value is absolute maximum and must not be exceeded in circuit design. Derating is required at elevated temperatures per the datasheet thermal characteristics table, and operation near this limit demands careful attention to transient voltage spikes and layout-induced inductance.

Does KSA1015OTA have a specified noise figure, and under what conditions?

Yes, the KSA1015OTA specifies a noise figure (NF) of 0.5–6 dB, measured at V_CE = −6 V, I_C = −0.1 mA, f = 100 Hz, and R_G = 10 kΩ. This makes it suitable for low-noise preamplifier applications where signal integrity at audio frequencies is critical, though actual NF depends on operating point and external circuit impedance matching.

How does the h_FE classification (GR/Y/O) affect KSA1015OTA performance in circuit design?

The KSA1015OTA is offered in three h_FE classifications: GR (200–400), Y (120–240), and O (70–140). The GR variant ensures highest gain stability in low-base-drive applications like microphone preamps, while O-class supports cost-sensitive switching where precise gain isn't critical. Designers must select based on required I_B budget and thermal sensitivity.

Is KSA1015OTA pin-compatible with KSC1815, and how are they used together?

Yes, the KSA1015OTA (PNP) and KSC1815 (NPN) share identical TO-92 packaging and complementary electrical ratings (same V_CEO, I_C, P_D). They are explicitly designed for pairing in push-pull output stages, differential amplifiers, and complementary bias networks - enabling symmetrical gain, offset cancellation, and simplified thermal management in discrete analog designs.

What is the thermal resistance and derating behavior of KSA1015OTA?

The KSA1015OTA has a junction-to-ambient thermal resistance (R_JA) of 312 °C/W on a standard FR-4 PCB (76 mm × 114 mm, 1.57 mm thick). Its power dissipation must be derated by 3.2 mW/°C above 25 °C ambient, meaning maximum usable P_D drops to ~240 mW at 75 °C ambient - a key constraint in enclosed or high-density layouts.