onsemi BC557_J05Z

Overview

BC557_J05Z from onsemi is a PNP epitaxial silicon transistor designed for general-purpose switching and linear amplification in low-power analog and digital circuits. It features V_CEO = −45 V, I_C = −100 mA, h_FE = 110–800 (Class A/B/C), V_CE(sat) ≤ −300 mV at I_C = −10 mA/I_B = −0.5 mA, and f_T = 150 MHz - enabling use in audio preamplifiers, level shifters, and discrete logic interfaces.

For engineers reviewing the BC557_J05Z datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92-3 package compatibility, complementary pairing with BC547 series, low-noise capability (NF = 2–10 dB at 1 kHz), and RoHS-compliant Pb-free construction.

Technical Context

The BC557_J05Z operates as a medium-voltage, medium-current PNP bipolar junction transistor optimized for DC-coupled gain stages and saturated-switching operation. Its h_FE classification (A/B/C) defines DC current gain ranges under V_CE = −5 V and I_C = −2 mA, while V_BE(on) = −600 to −750 mV ensures predictable turn-on behavior in emitter-follower or common-emitter configurations.

Thermal performance is defined by R_JA = 250 °C/W (FR-4 PCB, 76 mm × 114 mm), PD = 500 mW at 25°C with 4.0 mW/°C derating - supporting stable operation in ambient temperatures up to +125°C when power dissipation remains within limits. Cob = 6 pF at V_CB = −10 V enables moderate-frequency signal handling without excessive Miller effect.

Key Specifications

Pinout & Package

BC557_J05Z is housed in a TO-92-3 plastic package (Case 135AR), with standardized leadform orientation: flat side facing viewer, leads down, left-to-right pin order as Collector–Base–Emitter.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC557BTA and BC558BTA, BC557_J05Z offers identical performance to BC557BTA but with tape-and-reel packaging for production line efficiency, while maintaining superior voltage and frequency capability versus BC558BTA - making it optimal for new designs requiring reliability, manufacturability, and headroom.

Availability

BC557_J05Z is available at Aetrix Electronics and suitable for audio preamplification, discrete logic interfacing, LED driver circuits, and current mirror reference designs requiring stable component supply, consistent h_FE binning, and RoHS-compliant manufacturing.

Supply support for BC557_J05Z 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and consumer markets.

The BC557_J05Z belongs to onsemi's legacy BC5xx family of general-purpose bipolar transistors, engineered for robustness, consistency, and broad compatibility in discrete analog and mixed-signal designs across decades of industrial deployment.

FAQ

What is the maximum collector-emitter voltage rating for BC557_J05Z?

The BC557_J05Z has a maximum collector-emitter voltage (V_CEO) rating of −45 V. This value is confirmed in the Absolute Maximum Ratings table of the official onsemi datasheet (Rev. 3, June 2024). Exceeding this voltage risks permanent breakdown of the BC557_J05Z junction, especially under transient conditions or elevated temperature.

Is BC557_J05Z pin-compatible with BC547 series transistors?

BC557_J05Z is electrically complementary-not pin-compatible-with BC547 NPN transistors. While both use TO-92-3 packages, their pinouts differ: BC557_J05Z is C-B-E (left-to-right), whereas BC547 is E-B-C. Direct substitution without board revision will cause circuit failure. The BC557_J05Z is intended for pairing in push-pull or differential configurations, not drop-in replacement.

What h_FE class does BC557_J05Z correspond to?

BC557_J05Z corresponds to h_FE Class B, with a guaranteed DC current gain range of 200–450 at V_CE = −5 V and I_C = −2 mA. This classification is specified in the h_FE Classification table of the onsemi BC556–BC560 datasheet and applies directly to all BC557 variants including BC557_J05Z.

Does BC557_J05Z support surface-mount assembly?

BC557_J05Z is supplied in TO-92-3 package (Case 135AR) with bent leads suitable for through-hole mounting. Though not an SMT device, its tape-and-reel packaging (J05Z suffix) supports automated pick-and-place feeding into wave solder or selective solder processes - not reflow. For true SMT, consider SOT-23 alternatives like MMBT557, not BC557_J05Z.

What is the thermal resistance of BC557_J05Z in standard PCB layout?

The BC557_J05Z has a junction-to-ambient thermal resistance (R_JA) of 250 °C/W when mounted on a standard FR-4 PCB measuring 76 mm × 114 mm × 1.57 mm with minimum land pattern. This value assumes natural convection cooling and is used to calculate safe operating temperature rise: ΔT = R_JA × P_D. Derating begins above 25°C at 4.0 mW/°C.