onsemi SS9015CTA

Overview

SS9015CTA from Fairchild Semiconductor is a PNP epitaxial silicon transistor designed for low-frequency, low-noise amplification and switching in analog signal paths. It features V_CEO = −45 V, I_C = −100 mA, P_C = 450 mW, h_FE = 60–1000 (Class C), and f_T = 100–190 MHz - enabling use in audio preamplifiers, sensor interface stages, and discrete bias networks.

For engineers reviewing the SS9015CTA datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 package, complementary pairing with SS9014, low noise figure (0.7–10 dB at 1 kHz), and verified performance under V_CE = −5 V / I_C = −10 mA conditions.

Technical Context

The SS9015CTA operates as a general-purpose PNP bipolar junction transistor with fixed-emitter configuration and DC-coupled gain control. Its h_FE classification (C-grade: 200–600) ensures predictable current amplification across production lots, while low Cob (4.5–7.0 pF) and high f_T support stable operation up to mid-VHF frequencies without parasitic oscillation.

Designed for linear amplification, it delivers V_BE(sat) = −1.0 V and V_CE(sat) = −0.7 V at I_C = −100 mA / I_B = −5 mA, enabling efficient active-load switching in discrete power rails and emitter-follower buffers where thermal stability and low base drive loss are critical.

Key Specifications

Pinout & Package

SS9015CTA is housed in a standard TO-92 plastic package (3.86 mm × 1.27 mm × 4.58 mm), with leads formed for through-hole mounting and marked "SS9015" on the flat side. Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector - verified per Fairchild Rev. B2 datasheet and JEDEC TO-92 outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC557B and MPSA92, the SS9015CTA uniquely combines Class C h_FE (200–600), verified 0.7–10 dB noise figure, and 100–190 MHz f_T - making it the only option among the three qualified for low-noise, medium-frequency amplification in production audio and precision analog designs.

Availability

SS9015CTA is available at Aetrix Electronics and suitable for audio preamplifiers, sensor signal conditioners, and discrete bias networks requiring stable component supply and long-term obsolescence management.

Supply support for SS9015CTA 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 SS9015CTA belongs to Fairchild's legacy general-purpose bipolar transistor family, engineered specifically for low-noise, low-frequency linear amplification and complementary switching in cost-sensitive consumer and industrial electronics.

FAQ

What is the pin configuration of the SS9015CTA?

The SS9015CTA uses a standard TO-92 package with Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector - confirmed in Fairchild's Rev. B2 datasheet and consistent with JEDEC TO-92 mechanical outline. This configuration is fixed and non-reversible; incorrect orientation risks reverse-bias damage during operation.

Is the SS9015CTA suitable for low-noise audio applications?

Yes, the SS9015CTA is explicitly characterized for low-noise operation, with a noise figure of 0.7–10 dB at 1 kHz and R_S = 1 kΩ. Its Class C h_FE (200–600) and low Cob (4.5–7.0 pF) further support stable, high-SNR amplification in microphone preamps and line-level stages - as documented in Fairchild's SS9015 Rev. B2 datasheet.

How does the SS9015CTA differ from the SS9014?

The SS9015CTA is the PNP complement to the NPN SS9014, sharing identical TO-92 packaging, voltage ratings (V_CEO = −45 V / +45 V), and gain classification structure. Key differences include polarity inversion, slightly higher f_T (100–190 MHz vs. 80–150 MHz), and optimized noise performance for PNP-side signal paths in push-pull topologies.

What is the maximum power dissipation of the SS9015CTA?

The SS9015CTA has a maximum collector power dissipation (P_C) of 450 mW at T_A = 25°C. Derating is required above 25°C ambient - approximately 3.6 mW/°C - to maintain junction temperature ≤150°C. This rating assumes free-air convection and standard PCB copper area; forced-air cooling extends usable power range.

Can the SS9015CTA replace BC558 in existing designs?

The SS9015CTA can serve as a functional alternative to BC558 in many PNP switching and amplification roles, given matching V_CEO (−45 V), I_C (−100 mA), and TO-92 package. However, SS9015CTA offers higher h_FE (200–600 vs. 110–800) and verified low-noise specs - making it preferable where gain consistency or SNR matters, though layout compatibility must be confirmed per board footprint.