onsemi KSB1015O

Overview

KSB1015O from onsemi is a PNP epitaxial silicon power transistor designed for low-frequency amplifier and switching applications, featuring −60 V V_CEO, −3 A I_C, 25 W P_C at T_C = 25°C, h_FE of 60–120 at I_C = −0.5 A, and V_CE(sat) ≤ −1 V at I_C = −3 A / I_B = −0.3 A - used in audio output stages and relay drivers.

For engineers reviewing the KSB1015O datasheet, pinout, applications, or equivalent options, key selection criteria include safe operating area (SOA) compliance at −30 V/−1 A, thermal derating above 25°C case temperature, DC current gain stability across collector current range, and Pb-free TO-220 Fullpack mechanical compatibility.

Technical Context

This PNP bipolar junction transistor operates in linear amplification and saturated switching modes, with verified breakdown ratings of −60 V VCBO and VCEO, and guaranteed h_FE classification O (60–120) under V_CE = −5 V, I_C = −0.5 A conditions. Its f_T of 9 MHz supports low-frequency signal handling up to audio band.

Thermal performance is defined by junction-to-case thermal resistance (implied via 25 W P_C at T_C = 25°C), and SOA curves confirm pulsed operation capability up to 100 ms at −30 V/−1 A. Cob = 150 pF at V_CB = −10 V enables predictable high-frequency roll-off in amplifier feedback networks.

Key Specifications

Pinout & Package

Package: TO-220 Fullpack (Case 221AT), 3-lead, Pb-free, through-hole mount with integral heat sink tab (collector-connected). Mounting surface must be electrically isolated unless collector is referenced to chassis ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD127G and KSC2690Y, the KSB1015O offers superior thermal dissipation in through-hole layouts and guaranteed low-saturation performance critical for relay and motor control, while avoiding the polarity mismatch risk of using an NPN device in PNP-critical circuits.

Availability

KSB1015O is available at Aetrix Electronics and suitable for audio amplifier output stages, industrial relay drivers, and linear regulator pass elements requiring stable component supply and long-term manufacturability.

Supply support for KSB1015O 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, sensor, and logic solutions for automotive, industrial, and consumer markets.

The KSB1015O belongs to onsemi's general-purpose bipolar power transistor product line, engineered for robustness and consistency in linear amplification and medium-power switching applications where reliability under thermal stress is essential.

FAQ

What is the h_FE range for KSB1015O?

The KSB1015O is binned to the "O" classification, guaranteeing a DC current gain (h_FE) of 60 to 120 when measured at V_CE = −5 V and I_C = −0.5 A. This range is confirmed per the official onsemi datasheet KSB1015/D Rev. 2 and applies to every unit shipped as KSB1015O. Designers can rely on this specification for consistent base drive calculations without post-screening.

Is KSB1015O pin-compatible with other TO-220 PNP transistors like MJE172?

No, KSB1015O is not pin-compatible with MJE172. While both use TO-220 packages, KSB1015O has Base–Collector–Emitter pinout (1–2–3), whereas MJE172 uses Emitter–Base–Collector (1–2–3). Swapping them without PCB revision will cause circuit failure. Always verify pin assignment using the mechanical outline diagram in the KSB1015O datasheet before substitution.

Can KSB1015O be used in switching power supplies?

KSB1015O is rated for low-frequency operation (f_T = 9 MHz) and optimized for audio and relay switching, not high-frequency SMPS. Its t_ON/t_F values (0.4 µs / 0.5 µs) and lack of specified switching loss curves make it unsuitable for >50 kHz converters. For such applications, consider dedicated power MOSFETs or RF-optimized BJTs - KSB1015O should remain in its intended low-frequency domain.

Does KSB1015O require a heatsink in all applications?

A heatsink is required whenever power dissipation exceeds ~2 W continuously, based on its 25 W rating at T_C = 25°C and thermal derating curve. At ambient temperatures above 40°C or with >1 A DC collector current, junction temperature rises rapidly. The KSB1015O datasheet Figure 6 shows linear derating beyond 25°C - proper heatsinking prevents exceeding 150°C T_J and ensures long-term reliability.

What is the maximum safe operating voltage for KSB1015O in relay coil driving?

For relay coil driving, the KSB1015O supports up to −60 V V_CEO - meaning it safely blocks 60 V reverse voltage between collector and emitter. In practice, with typical 24 V relay coils and flyback diode protection, the device sees only brief inductive spikes; the −60 V rating provides ample margin against transient overshoot, making KSB1015O suitable for 24 V and 48 V industrial control systems.