onsemi BC327-40ZL1

Overview

BC327-40ZL1 from onsemi is a PNP epitaxial silicon transistor designed for switching and low-power amplification, with h_FE = 250–630 at I_C = −100 mA, V_CE = −1 V, V_CEO = −45 V, and P_D = 625 mW in TO-92 package. It serves as a complement to BC337/BC338 in push-pull audio driver stages and discrete logic-level switching circuits.

For engineers reviewing the BC327-40ZL1 datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed DC current gain range, collector-emitter saturation voltage under defined drive conditions, thermal resistance (R_JA = 200 °C/W), and Pb-free TO-92 mechanical compatibility.

Technical Context

This device operates as a medium-current, general-purpose PNP bipolar junction transistor with fixed-base biasing capability and linear amplification behavior up to f_T = 100 MHz. Its breakdown ratings (V_CEO = −45 V, V_CES = −50 V) and low V_CE(sat) (≤ −0.7 V at I_C = −500 mA, I_B = −50 mA) support reliable operation in saturated-switch and Class-A amplifier topologies.

The h_FE classification "40" denotes a minimum DC current gain of 250 at I_C = −100 mA and V_CE = −1 V, with typical gain retention down to −55 °C and up to 150 °C junction temperature. Output capacitance (C_ob = 12 pF at V_CB = −10 V) enables predictable high-frequency response in tuned or broadband small-signal applications.

Key Specifications

Pinout & Package

BC327-40ZL1 is housed in a Pb-free TO-92 (Case 135AN) plastic package with standard leadform: 4.825 mm × 4.76 mm footprint, axial leads, and through-hole mounting. Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter - verified per onsemi mechanical drawing 98AON13880G.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC327-40TA, BC327-40ZL1 offers straight-lead TO-92 compatibility for manual prototyping and legacy wave-solder lines; versus MMBT3906LT1G, it delivers 2× power handling and higher guaranteed h_FE, making it preferable for robust discrete amplifier and motor-control designs.

Availability

BC327-40ZL1 is available at Aetrix Electronics and suitable for audio amplifier drivers, discrete logic-level switches, DC motor control circuits, and linear regulator pass elements requiring stable component supply and long-term industrial availability.

Supply support for BC327-40ZL1 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 focused on energy-efficient electronics, with leadership in analog, power management, and discrete devices.

The BC327 series belongs to onsemi's general-purpose bipolar transistor product line, engineered for cost-sensitive, high-reliability linear and switching applications in consumer, industrial, and automotive subsystems.

FAQ

What is the maximum continuous collector current rating for BC327-40ZL1?

The BC327-40ZL1 has a maximum continuous collector current (I_C) rating of −800 mA at T_A = 25 °C. This rating assumes proper PCB thermal management; derating applies above 25 °C ambient per the 5.0 mW/°C thermal coefficient. Operation beyond this limit risks permanent degradation of h_FE and increased V_CE(sat). The BC327-40ZL1 must be used within its absolute maximum ratings to ensure reliability.

Does BC327-40ZL1 meet RoHS requirements?

Yes, BC327-40ZL1 is a Pb-free device compliant with the EU RoHS Directive 2011/65/EU. It uses lead-free terminations and packaging materials validated for compatibility with lead-free reflow and wave soldering profiles. The "ZL1" suffix explicitly denotes RoHS-compliant packaging per onsemi's ordering nomenclature. BC327-40ZL1 documentation confirms full exemption status for homogeneous material restrictions.

What is the guaranteed h_FE range for BC327-40ZL1 at I_C = −100 mA?

The BC327-40ZL1 is classified as "40", guaranteeing a DC current gain (h_FE) range of 250 to 630 when tested at V_CE = −1 V and I_C = −100 mA. This range is confirmed in the Electrical Characteristics table and supported by the h_FE Classification chart in the official datasheet. Designers can rely on BC327-40ZL1 to deliver ≥250 h_FE under these conditions.

Can BC327-40ZL1 replace BC327-25 in an existing design?

BC327-40ZL1 can replace BC327-25 only if the design requires higher minimum h_FE. BC327-25 guarantees h_FE = 100–250, while BC327-40ZL1 guarantees 250–630 - offering improved current gain consistency. All other electrical and mechanical parameters (V_CEO, P_D, package, pinout) are identical. No layout or schematic changes are needed for BC327-40ZL1 substitution into BC327-25 positions.

What is the thermal resistance junction-to-ambient (R_JA) for BC327-40ZL1?

The thermal resistance junction-to-ambient (R_JA) for BC327-40ZL1 is 200 °C/W, measured on a standard FR-4 PCB (76 mm × 114 mm × 1.57 mm) with minimum land pattern. This value enables calculation of junction temperature rise: T_J = T_A + (P_D × R_JA). At full 625 mW dissipation and 25 °C ambient, T_J reaches 156.25 °C - exceeding the 150 °C absolute max, so derating is mandatory. BC327-40ZL1 must operate below rated power at elevated ambient temperatures.