onsemi PN2907BU

Overview

PN2907BU from onsemi is a PNP general-purpose bipolar junction transistor designed for low-to-medium power switching and amplification, with −40 V V_CEO, −800 mA I_C, 625 mW P_D, h_FE = 30–300 (depending on I_C), and TO-92 package. It serves in discrete logic-level switching, relay drivers, and signal inversion circuits in industrial control and consumer power management.

For engineers reviewing the PN2907BU datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, guaranteed −40 V breakdown rating, thermal derating compliance (5.0 mW/°C), and RoHS-compliant Pb-free TO-92 packaging for legacy-compatible through-hole designs.

Technical Context

This device operates as a medium-current PNP BJT with base-emitter forward bias enabling collector current conduction up to −500 mA continuous. Its DC current gain varies nonlinearly with collector current-35 at −0.1 mA, 100–300 at −150 mA, dropping to 30 at −500 mA-reflecting typical gain compression under high drive.

Switching performance is characterized by 45 ns turn-on time, 80 ns storage time, and 100 ns total turn-off time under specified −15 mA base drive conditions. Output capacitance (C_ob = 8 pF) and input capacitance (C_ib = 30 pF) support operation up to ~100 MHz small-signal gain bandwidth.

Key Specifications

Pinout & Package

PN2907BU is housed in a standard TO-92 plastic package (Case 135AN), with 3-pin vertical lead configuration, 4.825 mm × 4.76 mm footprint, and E-B-C pin order (Emitter–Base–Collector) when viewed from front with flat side facing up and leads downward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBT2907A and PN2907A, PN2907BU offers the highest power dissipation (625 mW) in through-hole form factor, making it optimal for thermally demanding relay or LED driver applications where SMT thermal limits or h_FE variability are concerns.

Availability

PN2907BU is available at Aetrix Electronics and suitable for relay driver circuits, discrete logic inverters, LED current switches, and linear amplifier stages requiring stable component supply across industrial, automotive, and consumer electronics production cycles.

Supply support for PN2907BU 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, and discrete components for automotive, industrial, and cloud infrastructure markets.

PN2907BU belongs to onsemi's legacy general-purpose bipolar transistor product line, engineered for cost-sensitive, high-reliability through-hole applications where proven performance, wide temperature operation, and RoHS compliance are mandatory.

FAQ

What is the maximum continuous collector current rating for PN2907BU?

The PN2907BU has a maximum continuous collector current (I_C) rating of −800 mA at T_A = 25°C. This absolute maximum must be derated with ambient temperature using the specified 5.0 mW/°C thermal coefficient to ensure junction temperature stays within −55°C to +150°C limits. For sustained operation at −500 mA, heatsinking or airflow may be required depending on PCB layout and enclosure conditions. The PN2907BU datasheet confirms this rating under steady-state conditions.

Is PN2907BU RoHS compliant and lead-free?

Yes, PN2907BU is explicitly marked Pb-Free and RoHS compliant per onsemi's datasheet revision 5 (June 2024). It also meets Halogen Free/BFR Free and Beryllium Free requirements. The device uses lead-free solderable terminations and complies with EU Directive 2011/65/EU and related amendments. No exemptions apply, and the TO-92 package construction fully supports lead-free reflow and wave soldering processes. PN2907BU documentation confirms full environmental compliance without performance trade-offs.

What is the pin configuration of PN2907BU in the TO-92 package?

When viewing the PN2907BU TO-92 package from the front (flat side facing outward) with leads pointing downward, the pin order from left to right is Emitter (E), Base (B), Collector (C). This E-B-C configuration is standard for onsemi's PN2907BU and matches Case 135AN mechanical outline. Pin identification is confirmed by onsemi's marking diagram and mechanical drawings in the official datasheet. Always verify orientation before PCB layout or hand-soldering to avoid reverse-bias damage to the PN2907BU.

How does the DC current gain (h_FE) of PN2907BU vary with collector current?

The PN2907BU exhibits a non-linear h_FE curve: minimum 35 at −0.1 mA, 50 at −1.0 mA, 70 at −10 mA, 100–300 at −150 mA, and 30 at −500 mA (all at V_CE = −10 V, T_A = 25°C). This variation reflects typical BJT gain compression at high current densities. Designers must select base drive based on the target I_C point-e.g., −150 mA operation benefits from h_FE ≥ 100, while −500 mA requires larger I_B due to reduced gain. PN2907BU's datasheet provides these exact test conditions.

Can PN2907BU replace PN2907 in existing designs?

Yes, PN2907BU is a direct replacement for the legacy PN2907, sharing identical electrical specifications, TO-92 package, and E-B-C pinout. The "BU" suffix denotes onsemi's Pb-free, RoHS-compliant version with updated environmental compliance-no electrical or mechanical changes. All absolute maximum ratings, thermal characteristics, and electrical parameters match the original PN2907. PN2907BU maintains full backward compatibility in both schematic symbol and PCB footprint, requiring no redesign. Refer to onsemi's PN2907/D datasheet for cross-reference confirmation.