onsemi BC327-040G

Overview

BC327-040G from onsemi is a PNP silicon bipolar junction transistor (BJT) designed for general-purpose amplification and switching in low-voltage, medium-current applications. It features V_CEO = −45 V, I_C = −800 mA, h_FE = 250–630 (at I_C = −100 mA), V_CE(sat) = −0.7 V (at I_C = −500 mA, I_B = −50 mA), and f_T = 260 MHz - enabling use in audio preamplifiers, relay drivers, and logic-level interface circuits.

For engineers reviewing the BC327-040G datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE binning (−40 variant), Pb-free TO-92 packaging, thermal resistance (R_JA = 200 °C/W), safe operating area limits, and saturation voltage performance under defined drive conditions.

Technical Context

The BC327-040G operates as a discrete PNP BJT with fixed emitter-base and collector-base junction structures optimized for linear amplification and hard-switching. Its h_FE range (250–630 at I_C = −100 mA) reflects factory-sorted gain binning, distinguishing it from the BC327-16 and BC327-25 variants. The device exhibits V_BE(on) = −1.2 V and maintains stable f_T = 260 MHz under small-signal conditions.

Thermal design relies on R_JC = 83.3 °C/W and R_JA = 200 °C/W, with derating of 5.0 mW/°C above 25°C ambient when mounted on PCB without heatsink. Safe operating area (SOA) is defined up to 100 s pulse width, bounded by current limit, thermal limit, and second breakdown - critical for inductive load switching.

Key Specifications

Pinout & Package

BC327-040G is housed in a Pb-free TO-92 package (Case 29, Style 17), with standardized lead configuration and mechanical dimensions per ON Semiconductor's package drawing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP BJT switching and amplification applications.

Compared with BC327-040G, BC327-40ZL1G offers identical performance in alternate packaging, while MMBT327LT1G trades current capacity and thermal performance for miniaturization - making BC327-040G optimal for through-hole, medium-power, thermally demanding designs.

Availability

BC327-040G is available at Aetrix Electronics and suitable for audio preamplifiers, relay drivers, logic-level translators, and LED current-sink circuits requiring stable component supply, consistent h_FE binning, and RoHS-compliant through-hole packaging.

Supply support for BC327-040G 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 manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BC327 series belongs to onsemi's general-purpose bipolar transistor product line, engineered for cost-sensitive, high-reliability linear and switching applications across industrial controls, power supplies, and interface circuitry.

FAQ

What is the guaranteed h_FE range for BC327-040G?

The BC327-040G is binned to guarantee h_FE ≥ 250 at I_C = −100 mA and V_CE = −1.0 V, with typical values reaching 400 and maximum values up to 630. This binning ensures predictable base drive requirements in production-grade switching circuits - a key differentiator from the unsorted BC327 or lower-gain variants like BC327-16.

Is BC327-040G RoHS compliant and lead-free?

Yes, BC327-040G is explicitly marked as Pb-free in the ON Semiconductor datasheet and shipped in RoHS-compliant packaging. The "G" suffix denotes lead-free construction, verified per JEDEC J-STD-609 and compliant with EU Directive 2011/65/EU. No lead content is present in die attach, bond wires, or TO-92 lead frame plating.

Can BC327-040G replace BC327-25 in an existing design?

BC327-040G can replace BC327-25 only if the design benefits from higher minimum h_FE (250 vs. 160). Electrical ratings (V_CEO, I_C, P_D) are identical, and pinout is fully compatible. However, increased gain may alter bias point stability in linear amplifiers - verify quiescent operating point and thermal margin after substitution.

What is the maximum safe continuous collector current for BC327-040G?

The absolute maximum continuous collector current for BC327-040G is −800 mA at T_A = 25°C with no heatsink. At elevated ambient temperatures, derating applies: power dissipation must be reduced by 5.0 mW/°C above 25°C, limiting usable I_C in practice based on V_CE and board thermal design.

Does BC327-040G support switching inductive loads like relays?

Yes, BC327-040G is routinely used to drive relay coils, supported by its SOA curve covering 100 ms pulses and second-breakdown immunity. For reliable operation, always include a reverse-biased flyback diode across the coil, and confirm that peak I_C remains within −800 mA and V_CE does not exceed −45 V during turn-off transients.