Diodes Incorporated BC817-25-7

Overview

BC817-25-7 from Diodes Incorporated is a 45 V, 500 mA NPN small-signal transistor in SOT23 package, featuring h_FE = 160–400 at I_C = 100 mA and V_CE = 1.0 V, V_CE(SAT) ≤ 0.7 V at I_C = 500 mA/I_B = 50 mA, and f_T = 100 MHz - used for switching and audio-frequency amplification in automotive and industrial control circuits.

For engineers reviewing the BC817-25-7 datasheet, BC817-25-7 pinout, BC817-25-7 application, or BC817-25-7 equivalent, key selection criteria include DC current gain range, saturation voltage under high drive, thermal resistance (R_θJA = 403 °C/W), AEC-Q101 qualification, and SOT23 lead-free compliance.

Technical Context

This NPN bipolar junction transistor uses epitaxial planar die construction for stable gain and low leakage. It operates with V_CEO = 45 V and I_C = 500 mA continuous, supporting linear amplification and hard-switching modes across –65 °C to +150 °C ambient.

Its gain-bandwidth product of 100 MHz enables use in AF amplifiers up to ~20 kHz and fast digital switching (t_ON/t_OFF < 100 ns typical). The device is fully RoHS-compliant, halogen- and antimony-free, and qualified to AEC-Q101 for automotive reliability.

Key Specifications

Pinout & Package

SOT23 plastic surface-mount package with matte tin-plated leads, UL 94V-0 rated molding compound, and moisture sensitivity level 1 per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN small-signal transistor applications.

Compared with BC817-25-7, BC817-40-7-F offers higher gain for reduced base drive, while MMBT3904LT1G trades AEC-Q101 compliance for broader commercial availability - both retain SOT23 compatibility but differ in reliability assurance and gain targeting.

Availability

BC817-25-7 is available at Aetrix Electronics and suitable for automotive door modules, industrial PLC outputs, consumer audio preamps, and medical infusion pump motor drivers requiring stable component supply and long-term manufacturability.

Supply support for BC817-25-7 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the US.

The BC817 series belongs to Diodes' AEC-Q101-qualified small-signal transistor portfolio, engineered for reliable switching and amplification in harsh-environment automotive and industrial control systems.

FAQ

What is the maximum continuous collector current for BC817-25-7?

The BC817-25-7 is rated for 500 mA continuous collector current (I_C) at T_A = +25 °C. Derating applies above 25 °C ambient - power dissipation drops linearly to zero at 150 °C junction temperature, governed by R_θJA = 403 °C/W on standard FR-4 layout.

Is BC817-25-7 suitable for automotive applications?

Yes - BC817-25-7 is explicitly qualified to AEC-Q101 standards, including stress testing for temperature cycling, high-temperature operating life, and ESD (8 kV HBM). It carries the "AEC-Q101" marking and is listed in Diodes' automotive-grade product documentation.

How does the h_FE of BC817-25-7 compare to BC817-16-7-F and BC817-40-7-F?

At V_CE = 1.0 V and I_C = 100 mA, BC817-25-7 specifies h_FE = 160–400, sitting between BC817-16-7-F (100–250) and BC817-40-7-F (250–600). This mid-range gain provides balanced base drive requirements and tolerance to process variation.

Can BC817-25-7 replace BC847B in existing designs?

No - BC847B has V_CEO = 45 V but lower I_C = 100 mA and h_FE = 200–450. BC817-25-7's 500 mA rating and higher power dissipation (310 mW vs. 300 mW) allow it to handle heavier loads, but pinout compatibility alone doesn't guarantee functional equivalence without verifying bias network and thermal margins.