onsemi FJX1182OTF

Overview

FJX1182OTF from ON Semiconductor is a PNP epitaxial silicon transistor designed for low-frequency power amplification, with V_CEO = −30 V, I_C = −500 mA, P_C = 150 mW, and f_T = 200 MHz - used in audio preamplifier stages and relay driver circuits.

For engineers reviewing the FJX1182OTF datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain classification (O/Y), saturation voltage at high drive (V_CE(sat) ≤ −0.25 V @ I_C = −100 mA, I_B = −10 mA), and SOT-323 package thermal performance in space-constrained analog signal paths.

Technical Context

The FJX1182OTF operates as a medium-power PNP bipolar junction transistor optimized for linear amplification below 10 MHz, leveraging epitaxial base construction to achieve stable h_FE across I_C = −100 mA to −400 mA and low output capacitance (C_ob = 13 pF @ V_CB = −6 V).

Its design targets discrete gain stages where low V_BE(on) (−0.8 to −1.0 V @ I_C = −100 mA) and tight h_FE binning (70–140 for O grade; 120–240 for Y grade) support predictable biasing without feedback compensation in Class-A configurations.

Key Specifications

Pinout & Package

SOT-323 (SC-70) surface-mount package: 1.30 mm × 2.10 mm footprint, 0.95 mm height, 3-terminal configuration with gull-wing leads for reflow compatibility and manual inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with FJX1182OTF, MMBT3906LT1G trades current drive for voltage headroom and lacks graded h_FE, while DXT3906-7-F offers superior thermal handling in a non-drop-in footprint - both require schematic and layout review before substitution.

Availability

FJX1182OTF is available at Aetrix Electronics and suitable for audio preamplifiers, relay drivers, and LED current sources requiring stable component supply across industrial control, test equipment, and consumer electronics programs.

Supply support for FJX1182OTF 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 FJX1182OTF belongs to ON Semiconductor's legacy Fairchild discrete transistor portfolio, engineered specifically for cost-sensitive, medium-current linear and switching functions in analog signal conditioning and interface circuits.

FAQ

What is the maximum collector current rating for the FJX1182OTF?

The FJX1182OTF has a maximum continuous collector current (I_C) rating of −500 mA at T_A = 25°C. Derating is required above 25°C ambient, following the specified thermal resistance curve. This rating enables direct drive of moderate-power loads such as small relays or LED strings without external buffering. The FJX1182OTF must be operated within this limit to maintain reliability and avoid junction overheating.

Does the FJX1182OTF have a specified h_FE range for production lots?

Yes - the FJX1182OTF is binned into two h_FE classifications: O grade (70–140) and Y grade (120–240), both measured at V_CE = −1 V and I_C = −100 mA. These ranges are guaranteed per datasheet and reflected in device marking. The FJX1182OTF's O/Y grading allows designers to select units matching precise gain requirements for matched-pair amplifiers or bias-stable circuits.

What package type does the FJX1182OTF use, and what are its key mechanical dimensions?

The FJX1182OTF uses the SOT-323 (SC-70) surface-mount package: 2.10 mm × 1.30 mm body size, 0.95 mm height, and 0.65 mm lead pitch. Its three-terminal gull-wing leadform supports standard reflow profiles and optical inspection. The FJX1182OTF's compact footprint makes it suitable for high-density PCB layouts where thermal constraints permit its 150 mW power dissipation.

Can the FJX1182OTF be used in switching applications, and what is its typical V_CE(sat)?

Yes - the FJX1182OTF is qualified for switching use with V_CE(sat) ≤ −0.25 V at I_C = −100 mA and I_B = −10 mA. This low saturation voltage minimizes conduction loss and improves efficiency in digital output interfaces or relay drivers. The FJX1182OTF achieves fast turn-on/turn-off due to its epitaxial base and low C_ob, supporting clean edges up to several hundred kHz.

Is the FJX1182OTF suitable for automotive applications?

The FJX1182OTF is rated for storage temperatures from −55°C to +150°C and operates reliably across industrial temperature ranges. While not AEC-Q101 qualified, its robust junction temperature rating (T_J = 150°C) and stable h_FE make it usable in non-safety-critical automotive subsystems such as cabin lighting controls or HVAC interface circuits - provided system-level qualification is performed. The FJX1182OTF is not authorized for life-support or safety-critical vehicle functions.