onsemi BC558BRL1G

Overview

BC558BRL1G from onsemi is a PNP silicon general-purpose amplifier transistor in TO-92 package, rated for −30 V V_CEO, −30 V V_CBO, −5.0 V V_EBO, −100 mA I_C, and 360 MHz f_T. It delivers h_FE = 220–460 at I_C = −2.0 mA, V_CE = −5.0 V, and is commonly used in low-voltage analog signal amplification and switching stages of consumer audio preamps and sensor interface circuits.

For engineers reviewing the BC558BRL1G datasheet, pinout, applications, or equivalent options, this page provides verified electrical parameters, thermal performance data, TO-92 pin configuration, real-world use cases, and two validated alternative transistors with documented functional and parametric differences.

Technical Context

The BC558BRL1G operates as a discrete PNP bipolar junction transistor optimized for linear amplification and saturated switching in low-power analog and digital circuits. Its DC current gain (h_FE) is binned to B-series specification (220–460), and its f_T of 360 MHz supports high-frequency small-signal amplification up to mid-VHF range under I_C = −10 mA bias conditions.

Thermal design is constrained by R_JA = 200 °C/W (free-air) and R_JC = 83.3 °C/W, enabling 625 mW dissipation at T_A = 25°C with 5.0 mW/°C derating. Safe operating area (SOA) curves confirm reliable operation up to −100 mA / −30 V in single-pulse mode, limited by thermal and second-breakdown boundaries.

Key Specifications

Pinout & Package

BC558BRL1G uses the TO-92 (Case 29, Style 17) plastic package with bent leads and Pb-free finish. Dimensions conform to JEDEC TO-226 standard: 4.45–5.20 mm height, 4.32–5.33 mm width, 3.18–4.19 mm thickness.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC558BRL1G, BC558CRL1G offers higher guaranteed gain for precision biasing, while MMBT558LT1G trades thermal margin for board space savings-neither is pin-compatible due to differing packages, but both satisfy identical functional requirements in revised layouts.

Availability

BC558BRL1G is available at Aetrix Electronics and suitable for audio preamplifiers, sensor interface circuits, and LED driver switches requiring stable component supply across industrial, consumer, and automotive electronics programs.

Supply support for BC558BRL1G 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 BC558BRL1G belongs to onsemi's legacy BC5xx family of general-purpose bipolar transistors, designed for cost-sensitive, high-reliability linear and switching applications in analog signal chains and discrete logic interfaces.

FAQ

What is the maximum collector-emitter voltage rating for BC558BRL1G?

The BC558BRL1G has a maximum collector-emitter voltage (V_CEO) rating of −30 Vdc. This value is confirmed in the "Maximum Ratings" table of the official onsemi datasheet (Rev. 3, March 2007) and defines the absolute upper limit for DC bias across the collector and emitter terminals before breakdown occurs. Exceeding −30 V risks permanent device damage.

Does BC558BRL1G have Pb-free construction?

Yes, BC558BRL1G is manufactured with Pb-free packaging per the onsemi datasheet footnote and ordering information. The "G" suffix explicitly denotes RoHS-compliant, lead-free termination, and the device meets J-STD-020 moisture sensitivity level (MSL) 1 requirements for surface-mount assembly.

What is the h_FE range for BC558BRL1G at I_C = −2.0 mA?

The BC558BRL1G is binned to the B-series specification, with h_FE ranging from 220 to 460 when tested at I_C = −2.0 mAdc and V_CE = −5.0 Vdc. This range is specified in the "ELECTRICAL CHARACTERISTICS" table on page 2 of the official datasheet and is guaranteed for every unit shipped.

Can BC558BRL1G be used in switching applications?

Yes, BC558BRL1G is suitable for low-speed switching applications. Its V_CE(sat) is specified at −0.25 V max (I_C = −10 mAdc, I_B = −1.0 mAdc), and its SOA curve supports −100 mA pulses at −30 V. For reliable switching, base drive must ensure I_B ≥ I_C/10 to maintain saturation, and thermal limits must be observed per R_JA = 200 °C/W.

What is the thermal resistance junction-to-ambient for BC558BRL1G?

The thermal resistance junction-to-ambient (R_JA) for BC558BRL1G is 200 °C/W under free-air conditions, as stated in the "THERMAL CHARACTERISTICS" section of the datasheet. This value assumes no PCB copper pour or heatsinking; actual thermal performance improves with adequate copper area and airflow.