onsemi 2N5087_J18Z

Overview

2N5087_J18Z from ON Semiconductor (formerly Fairchild) is a PNP general-purpose amplifier transistor optimized for low-level, high-gain, low-noise signal amplification at collector currents up to 50 mA. It features V_CEO = −50 V, h_FE = 250 (at I_C = −1.0 mA), f_T = 40 MHz, V_CE(sat) = −0.3 V (at I_C = −10 mA), and C_cb = 4.0 pF - enabling precision analog front-ends in battery-powered instrumentation.

For engineers reviewing the 2N5087_J18Z datasheet, pinout, applications, or equivalent options, key selection criteria include its −50 V breakdown rating, guaranteed h_FE ≥ 250 at low bias, sub-0.3 V saturation voltage, 40 MHz gain-bandwidth product, and TO-92 package compatibility with legacy through-hole designs.

Technical Context

This device operates as a discrete PNP bipolar junction transistor with fixed-emitter configuration and common-emitter topology. Its design emphasizes low-noise performance (NF = 2.0 dB at I_C = −20 µA, R_S = 10 kΩ, 10 Hz–15.7 kHz) and stable DC current gain across temperature (−55 °C to +150 °C junction range).

Thermal resistance is specified as R_θJA = 200 °C/W on FR-4 PCB (1.6″ × 1.6″ × 0.06″), supporting continuous operation up to 625 mW at 25 °C ambient with linear derating. The −3.0 V V_EBO rating enables safe base-emitter reverse biasing in switching applications.

Key Specifications

Pinout & Package

2N5087_J18Z is housed in a TO-92 plastic package with 3 leads. Lead spacing matches JEDEC TO-92 standard (0.1" pitch), enabling drop-in replacement in legacy through-hole PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP general-purpose amplifier applications.

Compared with 2N5087_J18Z, MMBT5087 trades thermal robustness for board-space savings, while 2N5086 sacrifices gain headroom for cost reduction - making 2N5087_J18Z optimal for noise-critical, medium-gain analog designs requiring proven TO-92 reliability.

Availability

2N5087_J18Z is available at Aetrix Electronics and suitable for instrumentation amplifiers, low-voltage audio preamplifiers, precision current sources, and low-dropout linear regulator pass elements requiring stable component supply and long-term obsolescence management.

Supply support for 2N5087_J18Z 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 supplier of energy-efficient semiconductor solutions, specializing in power management, analog, and discrete devices for automotive, industrial, and consumer markets.

The 2N5087_J18Z belongs to Fairchild's legacy "FACT Quiet Series™" PNP amplifier family, engineered specifically for low-noise, high-gain analog signal conditioning in portable and precision measurement equipment.

FAQ

What is the maximum collector current rating for 2N5087_J18Z?

The 2N5087_J18Z has a continuous collector current rating of −100 mA per its Absolute Maximum Ratings table. However, its recommended operating condition for low-noise amplifier use caps I_C at −50 mA, aligning with the "low level, high gain, low noise" design intent documented in the device description. Exceeding −50 mA may degrade h_FE stability and increase noise figure beyond 2.0 dB.

Does 2N5087_J18Z support operation at elevated temperatures?

Yes, 2N5087_J18Z is rated for junction and storage temperatures from −55 °C to +150 °C. Its thermal resistance (R_θJA = 200 °C/W) allows full 625 mW dissipation at 25 °C ambient, with linear derating above that point. At 100 °C ambient, usable power drops to ~250 mW - sufficient for most Class-A amplifier and current-source applications.

Is 2N5087_J18Z pin-compatible with other TO-92 PNP transistors like 2N3906?

No, 2N5087_J18Z uses Emitter-Base-Collector (E-B-C) pinout (Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector), whereas 2N3906 uses Emitter-Collector-Base (E-C-B). Swapping them without board modification causes immediate circuit failure. Always verify pin assignment using the TO-92 marking diagram: 2N5087_J18Z is marked "2Q" and follows Fairchild's standard E-B-C sequence.

How does the noise performance of 2N5087_J18Z compare to modern JFETs?

At I_C = −20 µA and R_S = 10 kΩ, 2N5087_J18Z achieves 2.0 dB noise figure - competitive with low-noise JFETs like J310 in similar bias conditions. Its advantage lies in higher transconductance and simpler biasing, though JFETs offer lower input current noise. For voltage-noise-dominated sources (<1 kΩ), 2N5087_J18Z remains a viable discrete alternative.

Can 2N5087_J18Z be used in switching applications?

Yes, 2N5087_J18Z supports switching with V_CE(sat) = −0.3 V at I_C = −10 mA and I_B = −1.0 mA, yielding a forced β of 10. Its 40 MHz f_T allows turn-on/turn-off times under 100 ns in optimized layouts. However, it lacks specified switching parameters (t_on/t_off/t_f/t_r) - for critical high-speed switching, dedicated switching transistors like NSS12201LT1G are preferred.