PBSS4240T ZEW 40V 2A NPN Low VCEsat Transistor Innosilicon G1286 PSU

PBSS4240T ZEW NPN Transistor | Nexperia BISS Low-VCEsat for Innosilicon G1286 PSU Repair

The PBSS4240T (silk marking "ZEW") is a Nexperia (originally NXP Semiconductors) BISS (Breakthrough In Small Signal) NPN low-VCEsat transistor — the switching transistor used on the primary-side control stage of the Innosilicon G1286 power supply. The BISS family is engineered specifically for switching applications where collector-emitter saturation voltage (VCEsat) is the dominant loss term: at 1A continuous IC, the PBSS4240T's VCEsat sits around 0.5V — roughly half of what a conventional NPN would dissipate at the same load.

Per Nexperia's selection-guide datasheet, the PBSS4240T is rated VCEO 40V (50V max per some tables), IC 2A continuous (5A peak), with current gain hFE between 300 and 495 typical. The "ZEW" silk marking identifies this specific product code in the SMD package; alternate package variants (-Q automotive grade) exist with the same electrical specs.

Where the PBSS4240T Fits in G1286 PSU Repair

• Innosilicon G1286 PSU primary-side switching — the standard application driving the main MOSFET gate or auxiliary circuits.
• DC/DC converter stages on PSU secondary side — auxiliary rail generation.
• Battery management / power-cord switch circuits on related Innosilicon controller boards.
• Flash unit / motor drive auxiliary applications on hashboards using the same chip family.
• Repair-bench standard replacement for any failed BISS NPN footprint in the G1286 PSU.

Specs and Technical Features

• Manufacturer: Nexperia (formerly NXP Semiconductors) — BISS transistor family.
• Type: NPN bipolar junction transistor (low-VCEsat optimized).
• VCEO 40V (datasheet), VCEO max 50V per selection guides.
• IC 2A continuous, 5A peak.
• VCEsat ~0.5V at IC = 1A — significantly lower than conventional NPN equivalents.
• hFE current gain 300 to 495 typical — high-gain, ideal for switching control circuits.
• Operating temperature range consistent with industrial-grade BJT specs.
• "ZEW" SMD silk marking identifies the specific BISS variant.

PBSS4240T NPN Transistor Specifications

FAQ — PBSS4240T NPN Transistor

Q: What does "BISS" mean and why does it matter?
A: BISS stands for "Breakthrough In Small Signal" — Nexperia's marketing name for their family of low-VCEsat bipolar transistors. The low VCEsat (around 0.5V vs 1V+ for conventional NPN) cuts switching power loss roughly in half, which matters in continuously-operating PSU control circuits.

Q: Can I substitute PBSS5240T (the PNP complement)?
A: No — PBSS5240T is the PNP version, not NPN. They share the same family and package but conduct in opposite directions. If the PCB silk shows an NPN footprint, use PBSS4240T; if PNP, use PBSS5240T. The two parts are often used together in totem-pole / push-pull driver configurations.

Q: Is the "ZEW" marking critical for substitution?
A: The ZEW marking identifies the standard PBSS4240T variant. Some other suffixes (e.g. -Q for automotive grade) have the same electrical specs but different qualification. For repair work on the Innosilicon G1286 PSU, match the silk marking.

Q: How do I test the PBSS4240T in-circuit?
A: Power off the PSU, discharge caps. Use a multimeter in diode-test mode: Base → Emitter should read ~0.6-0.7V forward; Base → Collector should read ~0.6-0.7V forward; Collector → Emitter should read OL both ways. Any short or open indicates failure.

Q: Bulk pricing for repair shops?
A: Yes — email contact@lys-sz.com for tape-and-reel quantities.

Related products

• PBSS5240T ZFW PNP Transistor (Innosilicon G1286 PSU — complementary)
• IPW60R037P7 Infineon CoolMOS™ (G1240 PSU)
• 2SD882T-P NPN Transistor (Avalon Miner)
• G1266 / G1266A PSU (Innosilicon T2T)

Innosilicon G1286 PSU repair benches stocking PBSS4240T transistors in volume? Email contact@lys-sz.com for tape-and-reel pricing on Nexperia BISS stock. Worldwide shipping from our Shenzhen warehouse.