onsemi BC558CZL1

Overview

BC558CZL1 from onsemi is a PNP silicon small-signal amplifier transistor in TO-92 package, rated for V_CEO = −30 V, I_C = −100 mA continuous, h_FE = 420–800 at I_C = −2 mA, f_T = 360 MHz, and optimized for linear amplification in low-noise audio and signal conditioning stages.

For engineers reviewing the BC558CZL1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal limits, TO-92 terminal mapping, real-world use cases in bias-stable amplifiers and switching interfaces, and two validated alternative parts with documented performance trade-offs.

Technical Context

The BC558CZL1 operates as a general-purpose PNP bipolar junction transistor with fixed-emitter biasing capability, supporting both linear amplification (V_CE ≥ −1 V) and saturated switching (V_CE(sat) ≤ −0.25 V at I_C = −10 mA / I_B = −0.5 mA). Its h_FE binning (C-series) ensures tight DC current gain consistency across production lots.

Thermal design relies on R_JA = 200°C/W (ambient) and R_JC = 83.3°C/W (case), enabling 625 mW dissipation at T_A = 25°C or 1.5 W at T_C = 25°C - requiring heatsinking only above ~500 mW in ambient-air operation.

Key Specifications

Pinout & Package

BC558CZL1 uses the industry-standard TO-92 (Case 29, Style 17) plastic package with 3 leads, 4.45–5.20 mm height, and lead pitch of 2.54 mm. Mounting requires standard through-hole soldering with attention to thermal relief on collector pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP small-signal amplifier applications.

Compared with BC558CZL1, BC558BZL1 trades gain consistency for lower cost, while BC807-40W offers SMT scalability and higher voltage/current ratings at the expense of through-hole serviceability and legacy design compatibility.

Availability

BC558CZL1 is available at Aetrix Electronics and suitable for audio preamplifiers, industrial level-shifting interfaces, and precision DC bias generators requiring stable component supply and long-term obsolescence management.

Supply support for BC558CZL1 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, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BC558CZL1 belongs to the BC556/557/558 family of general-purpose PNP transistors designed for reliable, low-cost linear amplification and switching in cost-sensitive, high-volume applications such as consumer audio and industrial control.

FAQ

What is the maximum collector-emitter voltage rating for BC558CZL1?

The BC558CZL1 has a guaranteed V_CEO rating of −30 Vdc. This means the device can safely withstand up to 30 volts between collector and emitter with base open, making it suitable for circuits operating from −12 V or −15 V rails. Exceeding this voltage risks avalanche breakdown and permanent damage to the BC558CZL1.

Does BC558CZL1 support Pb-free soldering processes?

Yes, BC558CZL1 is manufactured in a Pb-free TO-92 package compliant with RoHS Directive 2011/65/EU. It supports standard reflow and wave soldering profiles per J-STD-020, with peak temperatures up to 260°C. The BC558CZL1G variant explicitly denotes Pb-free construction in its part number.

How does the h_FE binning of BC558CZL1 compare to BC558BZL1?

The BC558CZL1 is binned to the C-series h_FE specification: 420–800 at I_C = −2 mA, whereas BC558BZL1 is binned to B-series: 220–460. This means BC558CZL1 provides higher and tighter DC current gain, reducing variation in bias points across production units and minimizing need for manual gain trimming in the BC558CZL1-based design.

Can BC558CZL1 be used in switching applications?

Yes, BC558CZL1 is qualified for switching use with V_CE(sat) ≤ −0.25 V at I_C = −10 mA / I_B = −0.5 mA and I_CM = −200 mA peak. Its fast f_T of 360 MHz supports clean edge transitions up to ~10 MHz, though switching speed is ultimately limited by base drive strength and load capacitance in the BC558CZL1 implementation.

What thermal derating applies to BC558CZL1 above 25°C ambient?

BC558CZL1's total device dissipation must be derated by 5.0 mW/°C above T_A = 25°C when mounted on a standard PCB (R_JA = 200°C/W). For example, at 75°C ambient, maximum allowable power drops to 625 mW − (50 × 5.0) = 375 mW. Derating ensures junction temperature remains below 150°C and preserves reliability of the BC558CZL1.