onsemi KSB795OSTU

Overview

KSB795OSTU from Fairchild Semiconductor is a PNP epitaxial silicon Darlington transistor designed for audio frequency power amplification and low-speed industrial switching. It features V_CEO = −80 V, I_C = −1.5 A (DC), P_C = 10 W at T_C = 25°C, h_FE ≥ 2000 at I_C = −1 A, and V_CE(sat) = −1.5 V at I_C = −1 A / I_B = −1 mA - enabling high-current linear gain in compact TO-126 packages for amplifier output stages.

For engineers reviewing the KSB795OSTU datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE classification (Y-grade: 8000–30000), safe operating area (SOA) compliance up to 300 µs pulses, thermal derating behavior, and TO-126 mechanical compatibility with heatsink mounting requirements.

Technical Context

The KSB795OSTU integrates two cascaded PNP transistors in a monolithic Darlington configuration, delivering high DC current gain while maintaining single-base control. Its structure supports linear operation with low saturation voltage and robust secondary breakdown immunity, validated by SOA curves up to 100 µs pulse width.

Designed for fixed-bias or emitter-follower configurations, it operates with V_EB(off) ≤ −1.5 V for cutoff control and exhibits low leakage: I_CER ≤ −1 mA at V_CE = −60 V with R_BE = 51 Ω and T_C = 125°C - critical for stable biasing in temperature-varying industrial environments.

Key Specifications

Pinout & Package

Package: TO-126 - thermally optimized plastic power package with metal tab for direct heatsink mounting; dimensions 16.10 × 13.06 × 4.28 mm (L×W×H), tab-to-pin pitch 11.00 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD795T4G and BD795, the KSB795OSTU provides superior h_FE consistency and SOA integrity in the TO-126 form factor - making it optimal for space-constrained linear amplification and thermally managed industrial switching where gain stability and pulse reliability are design-critical.

Availability

KSB795OSTU is available at Aetrix Electronics and suitable for audio power amplifiers, industrial relay drivers, motor control snubbers, and linear voltage regulator pass elements requiring stable component supply and long-term manufacturability.

Supply support for KSB795OSTU 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 KSB795OSTU belongs to Fairchild's legacy audio and industrial power transistor family, engineered specifically for high-fidelity linear amplification and ruggedized low-speed switching in temperature-stable environments.

FAQ

What is the guaranteed h_FE range for KSB795OSTU?

The KSB795OSTU is Y-class binned with a guaranteed DC current gain (h_FE) of 8000–30000 at V_CE = −2 V and I_C = −1 A. This tight specification ensures predictable base drive requirements and stable bias points in audio output stages and precision switching circuits where gain variation must be minimized across temperature and unit-to-unit.

Is KSB795OSTU pin-compatible with KSB794OSTU?

Yes, KSB795OSTU and KSB794OSTU share identical TO-126 packaging, pinout (Emitter–Collector–Base), and mechanical dimensions. However, KSB795OSTU offers higher voltage ratings (V_CEO = −80 V vs. −60 V) and higher h_FE classification - making it a functional upgrade in designs requiring extended voltage headroom or improved gain consistency.

Can KSB795OSTU be used in surface-mount assemblies?

No - KSB795OSTU uses the through-hole TO-126 package with a metal tab designed for vertical mounting and heatsink attachment. It lacks SMT-compatible leads or thermal pads. For surface-mount alternatives, consider DPAK-packaged equivalents like MJD795, though these differ in pinout, thermal path, and gain specifications.

What is the maximum allowable case temperature for continuous operation of KSB795OSTU?

The KSB795OSTU has a maximum junction temperature of 150°C and a thermal resistance θ_JC of approximately 1.5°C/W. For continuous DC operation, the case temperature must remain ≤125°C to maintain ≥25°C safety margin - achievable with appropriate heatsinking per the derating curve in the original Fairchild datasheet Rev. A1.

Does KSB795OSTU require a base-emitter resistor for safe turn-off?

Yes - due to Darlington topology, residual charge can cause slow turn-off or latch-up. A 500 Ω resistor (R2 per datasheet schematic) between base and emitter is recommended to ensure rapid, reliable turn-off and prevent unintended conduction during signal transitions or noise events in industrial environments.