onsemi KSA1015OBU

Overview

KSA1015OBU from onsemi is a PNP epitaxial silicon transistor designed for low-frequency amplification and switching in analog signal paths, with confirmed V_CBO = −50 V, I_C = −150 mA, h_FE (Class O) = 70–140, and TO-92 package. It serves as a complementary pair to KSC1815 in dual-transistor amplifier stages and bias networks.

For engineers reviewing the KSA1015OBU datasheet, pinout, applications, or equivalent options, key selection criteria include its Class O h_FE range, −50 V breakdown ratings, 400 mW power dissipation, and verified suitability for audio preamplifier gain stages and relay driver interfaces.

Technical Context

This device operates as a general-purpose PNP bipolar junction transistor with fixed DC current gain classification (O = 70–140 at I_C = −2 mA), rated for continuous collector currents up to −150 mA and saturation voltages of V_CE(sat) ≤ −0.3 V at I_C = −100 mA/I_B = −10 mA.

Its f_T = 80 MHz supports stable operation in audio-band amplifiers and low-speed switching, while C_ob = 4–7 pF and NF = 0.5–6 dB at 100 Hz confirm suitability for low-noise, low-frequency signal conditioning where thermal stability and gain linearity are critical.

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 transistor applications.

Compared with KSA1015YTA and MPSA92, the KSA1015OBU provides the optimal balance of guaranteed low-noise performance, controlled h_FE spread, and −50 V robustness for cost-sensitive, low-frequency linear circuits-without over-spec'ing voltage or sacrificing gain predictability.

Availability

KSA1015OBU is available at Aetrix Electronics and suitable for audio preamplifier stages, relay driver interfaces, and discrete op-amp input pairs requiring stable component supply and consistent Class O h_FE performance.

Supply support for KSA1015OBU 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, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The KSA1015OBU belongs to onsemi's legacy general-purpose bipolar transistor family, engineered specifically for reliability and consistency in low-frequency analog signal conditioning and discrete power control applications.

FAQ

What is the h_FE range for KSA1015OBU?

The KSA1015OBU is binned to Class O, with a guaranteed DC current gain (h_FE) range of 70 to 140 when measured at V_CE = −6 V and I_C = −2 mA. This specification is explicitly defined in the onsemi datasheet and applies to every unit marked "O" in the device code. The KSA1015OBU's h_FE remains functional down to I_C = −150 mA (minimum 25), supporting both linear and switching modes.

Is KSA1015OBU pin-compatible with KSC1815?

No, the KSA1015OBU is not pin-compatible with KSC1815 - it is electrically complementary (PNP vs. NPN), not physically identical. Both use TO-92 packages, but their pinouts differ: KSA1015OBU has Emitter–Collector–Base (1–2–3), whereas KSC1815 uses Emitter–Base–Collector (1–2–3). PCB layout must account for this reversal to avoid wiring errors in complementary pair designs.

What is the maximum power dissipation for KSA1015OBU?

The KSA1015OBU has a maximum total device dissipation (P_D) of 400 mW at T_A = 25 °C, with a thermal derating factor of 3.2 mW/°C above that ambient temperature. This value is validated under standard FR-4 PCB conditions (76 mm × 114 mm, 1.57 mm thick). Exceeding P_D risks junction overheating beyond the 150 °C absolute maximum, potentially degrading h_FE or causing permanent failure.

Does KSA1015OBU support audio-frequency amplification?

Yes, the KSA1015OBU is explicitly characterized for low-frequency amplifier use, with f_T = 80 MHz and noise figure as low as 0.5 dB at 100 Hz. Its h_FE stability across I_C = −2 mA to −150 mA and V_CE(sat) ≤ −0.3 V make it suitable for high-fidelity preamplifier stages in 20 Hz–20 kHz applications - confirmed in onsemi's Typical Performance Characteristics (Figures 1–6).

What does the "O" suffix in KSA1015OBU signify?

"O" denotes the h_FE classification bin per onsemi's marking standard: KSA1015OBU guarantees h_FE = 70–140 at V_CE = −6 V and I_C = −2 mA. This binning enables predictable biasing in production designs without post-manufacture sorting. The "BU" suffix indicates tape-and-reel packaging (though original datasheet notes KSA1015GRTA/KSA1015YTA as discontinued; KSA1015OBU remains orderable via authorized channels).