BF421 overview

BF421 is a component documented by STMicroelectronics. The PDF description identifies it as "SMALL SIGNAL PNP TRANSISTOR Feb-2003." This guide condenses the most useful engineering information from the available PDF so that designers and sourcing teams can identify the checks that still need confirmation in the original document.

Datasheet snapshot

  • Manufacturer: STMicroelectronics
  • Part number: BF421
  • Category: IC
  • Datasheet length: 5 Pages

Specifications and operating details

The following points were extracted from the PDF text. Check the associated conditions, notes and limits in the complete document before using a value in a design.

  • Operating Junction Temperature 150 oC Ordering Code Marking Package / Shipment BF421 BF421 TO-92 / Bulk BF421-AP BF421 TO-92 / Ammopack TO-92 Bulk TO-92 Ammopack R thj-amb • R thj-Case • Thermal Resistance Junction-Ambient Max Thermal Resi.
  • Unit ICBO Collector Cut-off Current (IE = 0) V CB = -200 V V CB = -200 V TC = 150 oC V CB = -300 V -10 -10 -100 nA µ A µ A IEBO Emitter Cut-off Current (IC = 0) V EB = -5 V -50 nA V (BR)CEO ∗ Collector-Emitter Breakdown Voltage (IB = 0) IC.

Topics covered by the datasheet

The document includes sections related to:

  • APPLICATIONS

Engineering review checklist

  • Check resistance value, tolerance, temperature coefficient and long-term stability over the operating range.
  • Derate continuous power for ambient temperature and verify pulse or surge capability separately.
  • Match the land pattern, termination finish and current-sense routing to the exact package option.

Always confirm values against the latest manufacturer-controlled datasheet, especially when qualifying a substitute or releasing a production BOM.

View the complete PDF and model record

Open the BF421 datasheet and model details to review the complete PDF, document pages and available product information.

Source attribution

Adapted from the PDF associated with this DigiCamel model page.

Source model URL: https://www.digicamel.com/product.php?slug=bf421-stmicroelectronics

BF421 STMicroelectronics IC BF421 datasheet BF421 specifications BF421 applications