onsemi KSA733YIUTA

Overview

KSA733YIUTA from ON Semiconductor is a PNP epitaxial silicon transistor designed for low-frequency amplification and switching applications, with V_CEO = −50 V, I_C = −150 mA, P_C = 250 mW, h_FE = 350–700 (Y-class), and TO-92 package. It serves as a complement to the NPN KSC945 in push-pull amplifier stages and discrete bias networks.

For engineers reviewing the KSA733YIUTA datasheet, pinout, applications, or equivalent options, key selection criteria include its Y-class h_FE binning, low V_CE(sat) (−0.18 V min at I_C = −100 mA), noise figure (6.0–20 dB), and TO-92 mechanical compatibility in space-constrained analog signal paths.

Technical Context

The KSA733YIUTA operates as a general-purpose PNP bipolar junction transistor optimized for audio preamplifier stages, level-shifting circuits, and discrete current-sink drivers. Its f_T of 50–180 MHz supports stable gain up to mid-audio frequencies, while Cob = 2.8 pF ensures minimal Miller effect in common-emitter configurations.

It features a fixed emitter-base breakdown voltage (BVEBO = −5 V) and collector-base breakdown (BVCBO = −60 V), enabling reliable operation in negative-rail biasing schemes. The device's R/O/Y/G/L h_FE classification system confirms its Y-bin assignment (h_FE = 350–700), verified per test condition V_CE = −6 V, I_C = −1 mA.

Key Specifications

Pinout & Package

Package: TO-92 (3-lead plastic through-hole), lead configuration: Emitter–Base–Collector (1–2–3), body length 4.58 mm max, lead pitch 1.27 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KSA733OTA and MPSA92, the KSA733YIUTA delivers the highest guaranteed h_FE range (350–700) and lowest V_CE(sat), making it optimal for low-noise, medium-current linear amplification where gain stability and efficiency are prioritized over ultra-high voltage rating.

Availability

KSA733YIUTA is available at Aetrix Electronics and suitable for audio preamplifier design, discrete level-shifting circuits, and LED constant-current sink applications requiring stable component supply and long-term manufacturability.

Supply support for KSA733YIUTA 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

ON Semiconductor (formerly Fairchild Semiconductor) is a global leader in intelligent power and sensing solutions, serving automotive, industrial, cloud, and consumer markets with energy-efficient semiconductor technologies.

The KSA733YIUTA belongs to ON Semiconductor's legacy general-purpose bipolar transistor family, engineered for reliability and consistency in analog signal conditioning, discrete power control, and complementary amplifier topologies.

FAQ

What is the pin configuration of the KSA733YIUTA?

The KSA733YIUTA uses a TO-92 package with pin 1 = Emitter, pin 2 = Base, pin 3 = Collector. This emitter–base–collector order is confirmed in the official ON Semiconductor datasheet Rev. A2 and matches the "suffix -C" designation meaning center-collector variant. Always verify orientation via the flat side and lead-down view before PCB layout.

What does the 'Y' in KSA733YIUTA signify?

'Y' denotes the h_FE gain bin: KSA733YIUTA is factory-tested and binned to guarantee DC current gain between 350 and 700 at V_CE = −6 V and I_C = −1 mA. This distinguishes it from O-class (70–140) or G-class (200–400) variants and ensures predictable biasing in high-gain amplifier stages.

Is KSA733YIUTA a direct replacement for KSC945?

No - KSA733YIUTA is the PNP complement to the NPN KSC945, not a replacement. They are paired in push-pull or differential amplifier configurations. Substituting KSA733YIUTA for KSC945 would invert circuit functionality and likely cause failure due to polarity mismatch and incompatible bias requirements.

What is the maximum power dissipation of KSA733YIUTA at 25°C ambient?

The KSA733YIUTA has a rated collector power dissipation (P_C) of 250 mW at T_A = 25°C with no heatsink. Derating is required above 25°C - approximately 2.0 mW/°C - per the datasheet's thermal resistance curve. Actual usable power depends on PCB copper area, airflow, and mounting method.

Does KSA733YIUTA support high-frequency signal amplification?

The KSA733YIUTA has an f_T of 50–180 MHz, but its intended use is low-frequency amplification (≤100 kHz). While usable at higher frequencies, gain rolls off significantly beyond 1 MHz due to Cob = 2.8 pF and package parasitics; it is not recommended for RF or fast digital switching applications.