onsemi BC640_J61Z

Overview

BC640_J61Z from Fairchild Semiconductor is a PNP epitaxial silicon transistor designed for linear amplification and switching in low-voltage, medium-current circuits. It delivers V_CEO = −80 V, I_C = −1 A, h_FE = 25–160 (at I_C = −5 mA to −500 mA), and V_CE(sat) = −0.5 V at I_C = −500 mA / I_B = −50 mA - enabling robust operation in relay drivers and audio preamplifiers.

For engineers reviewing the BC640_J61Z datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package compatibility, guaranteed h_FE range across collector current, V_CEO/V_CER ratings for safe margin in inductive load switching, and complementary pairing with BC639 in push-pull stages.

Technical Context

This discrete PNP bipolar junction transistor operates in active, saturation, and cutoff regions with defined DC gain linearity across three test points (I_C = −5 mA, −150 mA, −500 mA). Its f_T = 100 MHz supports RF amplifier use up to ~30 MHz with stable gain, while V_BE(on) = −1 V at I_C = −500 mA enables predictable base drive design.

The device features low leakage (I_CBO ≤ −0.1 μA at V_CB = −30 V) and thermal stability up to T_J = 150°C, with power dissipation rated at 1 W under free-air conditions - requiring minimal heatsinking in <1 W switching applications.

Key Specifications

Pinout & Package

BC640_J61Z is housed in a standard TO-92 plastic package with 3 leads, compatible with through-hole assembly and manual prototyping. Lead spacing matches JEDEC TO-92 outline (1.27 mm pitch), and mechanical dimensions are fully specified per Fairchild Rev. C3 documentation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC640TA (identical function, packaging variant) and MPSA92 (higher voltage, lower gain), BC640_J61Z offers optimal balance of gain linearity, saturation performance, and cost for general-purpose PNP switching and amplification below 80 V.

Availability

BC640_J61Z is available at Aetrix Electronics and suitable for audio preamplifiers, relay drivers, DC motor controllers, and LED current regulators requiring stable component supply and long-term industrial availability.

Supply support for BC640_J61Z 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The BC640_J61Z belongs to Fairchild's legacy general-purpose bipolar transistor family, engineered for reliability in industrial control, consumer audio, and electro-mechanical interface applications.

FAQ

What is the pin configuration of BC640_J61Z?

BC640_J61Z uses the standard TO-92 pinout: Pin 1 is Emitter, Pin 2 is Collector, and Pin 3 is Base - verified per Fairchild BC640 Rev. C3 datasheet mechanical drawings and marking diagrams. This configuration is consistent across all BC640 variants including BC640_J61Z, BC640TA, and BC640TAR.

Is BC640_J61Z RoHS compliant?

Yes, BC640_J61Z meets RoHS Directive 2011/65/EU requirements as confirmed by Fairchild's compliance documentation archived under part number BC640. The TO-92 package contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits.

Can BC640_J61Z replace BC639 in a circuit?

No - BC640_J61Z is a PNP transistor and BC639 is its NPN complement; they are not direct replacements. Swapping them would invert logic polarity and likely cause circuit failure. BC640_J61Z is intended for use *with* BC639 in complementary pairs, not instead of it.

What is the maximum junction temperature for BC640_J61Z?

The maximum rated junction temperature for BC640_J61Z is 150°C, as specified in the Absolute Maximum Ratings table of the Fairchild BC640 Rev. C3 datasheet. Derating is required above 25°C ambient, with thermal resistance R_θJA ≈ 200°C/W typical for TO-92 in still air.

Does BC640_J61Z have a documented SPICE model?

Yes, Fairchild provided a validated PSpice model for the BC640 family (including BC640_J61Z) in their legacy simulation library, covering DC, AC, and transient behavior. Model parameters align with measured h_FE, V_CE(sat), and f_T values from the BC640 Rev. C3 datasheet.