onsemi KSA733CYBU

Overview

KSA733CYBU from ON Semiconductor is a PNP epitaxial silicon transistor in TO-92 package, rated for -50 V V_CEO, -150 mA I_C, 250 mW P_C, with h_FE range 350–700 (Y-class), and f_T up to 180 MHz. It serves as a low-frequency amplifier and complement to KSC945 in discrete bias networks and signal conditioning stages.

For engineers reviewing the KSA733CYBU datasheet, pinout, applications, or equivalent options, key selection criteria include its Y-class h_FE binning, -0.18 V typical V_CE(sat) at -100 mA/-10 mA drive, -0.62 V typical V_BE(on), and 2.8 pF Cob - all critical for low-noise analog gain and switching efficiency in compact through-hole designs.

Technical Context

The KSA733CYBU operates as a general-purpose PNP bipolar junction transistor optimized for linear amplification and switching in DC-coupled, low-frequency (<10 MHz) circuits. Its design emphasizes stable h_FE across collector currents from -0.3 mA to -100 mA and low saturation voltage under moderate base drive.

It features a center-collector TO-92 configuration (pinout: 1–Emitter, 2–Base, 3–Collector), enabling direct pairing with NPN complements like KSC945 in push-pull or differential pair topologies. Junction temperature rating of 150°C supports operation in thermally constrained industrial and consumer enclosures.

Key Specifications

Pinout & Package

Package: TO-92, center-collector variant (suffix "C"); body dimensions 4.58 mm × 3.60 mm × 14.47 mm; lead pitch 1.27 mm; RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KSA733YTA and MPSA92, the KSA733CYBU delivers superior h_FE consistency (350–700) and lower noise for precision analog use, while maintaining identical TO-92 mounting and pin compatibility with KSC945 - making it optimal for production-grade low-frequency amplifier and bias circuits where repeatability matters.

Availability

KSA733CYBU is available at Aetrix Electronics and suitable for audio pre-amplifier stages, discrete bias networks, and LED driver switches requiring stable component supply, consistent h_FE binning, and through-hole manufacturability.

Supply support for KSA733CYBU 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and edge applications.

The KSA733CYBU belongs to ON Semiconductor's legacy general-purpose bipolar transistor family, designed specifically for cost-sensitive, high-reliability analog signal conditioning and discrete switching in consumer and industrial equipment.

FAQ

What is the pin configuration of the KSA733CYBU?

The KSA733CYBU uses a TO-92 package with center-collector pinout: Pin 1 is Emitter, Pin 2 is Base, and Pin 3 is Collector. This configuration is explicitly defined in the Fairchild/ON Semiconductor datasheet Rev. A2 and matches the "-C" suffix designation. The KSA733CYBU pinout enables direct mechanical and electrical pairing with complementary NPN devices like KSC945 in dual-transistor circuits.

What does the "Y" in KSA733CYBU signify?

"Y" denotes the h_FE gain bin: for the KSA733CYBU, h_FE is guaranteed between 350 and 700 at V_CE = -6 V and I_C = -1 mA. This tight binning improves predictability in amplifier biasing and reduces calibration effort in production. The "Y" grade is distinct from "R", "O", "G", or "L" bins listed in the same datasheet, and applies exclusively to the KSA733CYBU variant.

Is the KSA733CYBU RoHS compliant?

Yes, the KSA733CYBU is RoHS compliant, as confirmed by ON Semiconductor's official product change notices and packaging documentation. Its TO-92 package uses lead-free terminations and complies with Directive 2011/65/EU. No exemptions apply, and the device carries the standard RoHS marking on reel labels and shipping documentation for the KSA733CYBU.

Can the KSA733CYBU replace the KSA733YTA in existing designs?

The KSA733CYBU can replace the KSA733YTA only if the design relies on high h_FE (350–700 vs. 120–240). Gain-dependent circuits - such as emitter-follower buffers or fixed-bias amplifiers - may require resistor value adjustments. Both share identical package, pinout, and absolute maximum ratings, so no PCB changes are needed, but functional validation of DC operating points is required for the KSA733CYBU.

What is the maximum operating frequency for small-signal amplification with the KSA733CYBU?

The KSA733CYBU has an f_T of 50–180 MHz, but its usable small-signal amplification bandwidth is limited to ≤10 MHz due to decreasing h_FE and rising distortion above that point. For audio and low-speed control signal amplification (e.g., sensor outputs, PWM filtering), the KSA733CYBU performs reliably up to 5 MHz with <1% THD; beyond that, gain roll-off and phase shift become significant.