onsemi BC327

Overview

BC327−40ZL1G from onsemi is a PNP silicon general-purpose amplifier transistor in TO-92 package, rated for −45 V_CEO, −800 mA continuous collector current, and 625 mW power dissipation at 25°C ambient. It delivers h_FE = 250–400 at I_C = −300 mA and V_CE = −1.0 V, with V_CE(sat) ≤ −0.7 V at I_C = −500 mA / I_B = −50 mA, supporting low-loss switching and linear amplification in discrete bias networks.

For engineers reviewing the BC327−40ZL1G datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed DC current gain binning (−40 variant), thermal resistance (R_JA = 200°C/W), safe operating area limits, Pb-free TO-92 packaging, and compatibility with through-hole PCB assembly and industrial temperature range (−55°C to +150°C).

Technical Context

The BC327−40ZL1G operates as a medium-power PNP bipolar junction transistor optimized for linear amplification and saturated switching. Its design centers on stable h_FE performance across collector currents up to −300 mA, low V_CE(sat) under high drive conditions, and robust secondary breakdown immunity per Figure 2 of the datasheet.

It features a fixed three-terminal structure with defined thermal path (R_JC = 83.3°C/W), junction-to-ambient thermal resistance suitable for natural-convection heatsinking, and small-signal f_T = 260 MHz enabling use in audio-frequency amplifiers and low-speed digital interfaces.

Key Specifications

Pinout & Package

BC327−40ZL1G uses the TO-92 (Case 29-11, Style 17) plastic package with 3 leads, lead spacing 2.54 mm, and standard through-hole mounting. Pin 1 is Collector, Pin 2 is Base, Pin 3 is Emitter - confirmed by marking diagram and package dimensions page of BC327/D Rev. 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC327−40RL1G, BC327−40ZL1G offers identical electrical performance but superior thermal handling in free-air environments due to TO-92's lower R_JA; versus BC807−40LT1G, it delivers 2× power capability and easier manual prototyping, though at larger board area cost.

Availability

BC327−40ZL1G is available at Aetrix Electronics and suitable for relay driver circuits, LED current sink drivers, audio pre-amplifier stages, and level translation interfaces requiring stable component supply, long-term manufacturability, and RoHS-compliant through-hole transistors.

Supply support for BC327−40ZL1G 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, sensors, and connectivity solutions for automotive, industrial, and consumer markets.

The BC327−40ZL1G belongs to onsemi's legacy general-purpose bipolar transistor family, designed for cost-sensitive, high-reliability discrete amplification and switching in industrial control, power supplies, and signal conditioning applications.

FAQ

What is the guaranteed h_FE range for BC327−40ZL1G?

The BC327−40ZL1G is binned to guarantee h_FE = 250–400 at I_C = −300 mA and V_CE = −1.0 V, as specified in the Electrical Characteristics table of the BC327/D Rev. 3 datasheet. This bin distinguishes it from BC327−16 (h_FE = 100–250) and BC327−25 (h_FE = 160–400). The BC327−40ZL1G's tighter gain spread improves predictability in analog feedback and current mirror designs.

Is BC327−40ZL1G RoHS compliant?

Yes, BC327−40ZL1G is RoHS compliant and marked with the "G" suffix indicating Pb-free terminations. Its TO-92 package meets JESD97 and JEDEC standards for lead-free soldering, including compatibility with both SnPb and lead-free reflow profiles. The device complies with EU Directive 2011/65/EU and subsequent amendments, as confirmed in the Ordering Information section of the BC327/D datasheet.

What is the maximum power dissipation of BC327−40ZL1G at 75°C ambient?

At T_A = 75°C, BC327−40ZL1G's maximum power dissipation is 375 mW. This is calculated from its 625 mW rating at 25°C and 5.0 mW/°C derating factor: 625 mW − (50°C × 5.0 mW/°C) = 375 mW. Exceeding this value risks junction temperature exceeding 150°C, triggering thermal shutdown or permanent degradation. The BC327−40ZL1G's R_JA = 200°C/W confirms this linear derating behavior.

Can BC327−40ZL1G replace BC327−25 in existing designs?

BC327−40ZL1G can replace BC327−25 in most designs because both share identical absolute maximum ratings, package, pinout, and SOA curves; the only difference is guaranteed h_FE (250–400 vs. 160–400). If the original design relies on minimum h_FE ≥ 160, BC327−40ZL1G's higher minimum (250) improves margin. However, verify base drive compliance, as higher h_FE may reduce required I_B in saturated switching applications.

What is the safe operating area (SOA) limit for BC327−40ZL1G at DC operation?

Per Figure 2 of the BC327/D datasheet, the BC327−40ZL1G's DC SOA limit is defined by thermal and second-breakdown boundaries: at V_CE = −1.0 V, it supports up to −1000 mA continuously; at V_CE = −10 V, max I_C drops to −100 mA. These limits assume T_C = 25°C and account for both junction heating and localized hot-spot formation. The BC327−40ZL1G must not exceed these coordinates to avoid irreversible failure.