onsemi BC327ZL1G

Overview

BC327ZL1G from onsemi is a PNP silicon bipolar junction transistor designed for general-purpose amplification and switching in low-voltage, medium-current circuits. It features −45 V V_CEO, −800 mA I_C, 1.5 W P_D at T_A = 25°C, h_FE = 100–630 (depending on variant), and TO-92 package. It is commonly used in discrete power stage drivers, relay interface circuits, and linear regulator pass elements.

For engineers reviewing the BC327ZL1G datasheet, pinout, applications, or equivalent options, key selection criteria include verified DC current gain across operating current ranges, saturation voltage under defined I_C/I_B conditions, thermal resistance (R_JA = 200°C/W), and Pb-free TO-92 mechanical compatibility with legacy through-hole layouts.

Technical Context

The BC327ZL1G operates as a standard PNP BJT with fixed emitter-base and collector-base junctions, requiring external base current control to regulate collector current flow. Its safe operating area (SOA) is bounded by thermal limits (T_J ≤ 150°C), second breakdown, and current/voltage constraints - notably −45 V V_CEO and −800 mA I_C.

It exhibits f_T = 260 MHz at I_C = −10 mA, V_CE = −5 V, supporting audio-frequency amplification and moderate-speed switching. Cob = 11 pF and V_BE(on) = −1.2 V (at I_C = −300 mA) define its small-signal input impedance and turn-on threshold behavior in active-mode biasing.

Key Specifications

Pinout & Package

BC327ZL1G is housed in a Pb-free TO-92 package (Case 29, Style 17), with standardized lead spacing and mechanical dimensions compliant with ANSI Y14.5M. The package supports manual soldering and wave soldering per onsemi's Pb-free guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC327-25ZL1G and MMBT3906LT1G, BC327ZL1G provides optimal balance of legacy TO-92 compatibility, 800 mA current handling, and 1.5 W power capability - making it the default choice for cost-sensitive, medium-current through-hole BJT applications where gain ≥100 suffices.

Availability

BC327ZL1G is available at Aetrix Electronics and suitable for relay interface circuits, linear regulator pass elements, LED current sink arrays, and audio inverter stages requiring stable component supply and long-term manufacturability.

Supply support for BC327ZL1G 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, cloud, and consumer markets.

The BC327 family belongs to onsemi's general-purpose bipolar transistor product line, engineered for reliability and consistency in discrete amplifier and switching applications across commercial and industrial temperature ranges.

FAQ

What is the maximum collector current rating for BC327ZL1G?

The BC327ZL1G has a maximum continuous collector current (I_C) rating of −800 mA at T_A = 25°C. This value decreases with rising ambient temperature due to thermal derating (12 mW/°C). At 75°C ambient, the usable I_C drops to approximately −600 mA to maintain junction temperature within 150°C. Always verify actual dissipation using V_CE(sat) and layout thermal performance in final design.

Does BC327ZL1G have Pb-free construction?

Yes, BC327ZL1G is explicitly marked as Pb-free in onsemi's ordering information and conforms to RoHS Directive 2011/65/EU. Its TO-92 package uses lead-free terminations and complies with JEDEC J-STD-020 moisture sensitivity level (MSL) requirements for standard through-hole assembly processes.

What is the DC current gain (h_FE) range for BC327ZL1G?

BC327ZL1G corresponds to the base BC327 variant, with h_FE ranging from 100 (minimum) to 630 (maximum) at I_C = −100 mA and V_CE = −1.0 V. Typical h_FE is 250 under those conditions. Gain varies with operating point - e.g., h_FE drops to ~160 at I_C = −300 mA, necessitating design margin in high-current bias networks.

Can BC327ZL1G be used in switching applications?

Yes, BC327ZL1G is routinely used in saturated switching applications such as relay drivers and LED sinks. Its V_CE(sat) = −0.7 V at I_C = −500 mA/I_B = −50 mA ensures low conduction loss. For reliable switching, ensure base drive provides I_B ≥ I_C/10, and verify SOA boundaries (especially second breakdown) in pulsed operation per Figure 2 of the datasheet.

What is the thermal resistance (R_JA) of BC327ZL1G?

The BC327ZL1G has a junction-to-ambient thermal resistance (R_JA) of 200°C/W in free-air conditions, as specified in the Thermal Characteristics table. This value assumes standard TO-92 mounting on FR-4 PCB with no copper pour. Adding 1 cm² of 2-oz copper connected to the emitter pad reduces R_JA to ~120°C/W, enabling higher continuous power handling.