Nexperia USA Inc. BC817-25W,115

Overview

BC817-25W from Nexperia is a 45 V, 500 mA NPN general-purpose transistor in SOT323 (SC-70) package, optimized for low-power switching and linear amplification with h_FE of 160–400 at V_CE = 1 V and I_C = 100 mA. It delivers 700 mV V_CE(sat) at I_C = 500 mA / I_B = 50 mA and supports 100 MHz f_T, enabling use in compact DC-DC bias networks and sensor interface stages.

For engineers reviewing the BC817-25W datasheet, BC817-25W pinout, BC817-25W application, or BC817-25W equivalent, this page provides verified pin functions, thermal derating curves, h_FE distribution across temperature, V_BE(sat) vs. I_C behavior, and direct alternatives with validated gain-bandwidth trade-offs.

Technical Context

This discrete NPN bipolar junction transistor operates in active, saturation, and cutoff regions with defined absolute maximum ratings: 45 V V_CEO, 500 mA continuous I_C, and 150 °C T_j. Its pulsed I_CM reaches 1 A (t_p ≤ 1 ms), supporting short-duration load switching.

Thermal performance is characterized by R_th(j-a) = 625 K/W on standard FR4 PCB and 431 K/W with 1 cm² collector pad. The device exhibits 3 pF C_c at V_CB = 10 V, enabling stable operation up to 100 MHz f_T under specified bias conditions.

Key Specifications

Pinout & Package

SOT323 (SC-70) plastic surface-mounted package: 1.35 mm × 2.2 mm footprint, 0.65 mm pitch, 0.9 mm height; designed for reflow soldering with standardized land pattern per Fig. 17.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose transistor applications.

Compared with BC817-16W and BC817-40W, the BC817-25W offers balanced h_FE (160–400) that simplifies base resistor design for both switching and amplification, avoids excessive gain-induced instability in feedback loops, and maintains adequate drive margin across temperature without over-specifying base current.

Availability

BC817-25W is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller GPIO expansion, relay coil control, and level-shifting interfaces requiring stable component supply across industrial, consumer, and medical electronics programs.

Supply support for BC817-25W 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with manufacturing rooted in process control and automotive-grade quality systems.

The BC817W series targets cost-sensitive, space-constrained applications needing proven NPN switching and amplification performance in ultra-small packages-designed specifically for consumer portables, IoT edge nodes, and industrial control subsystems.

FAQ

What is the maximum allowable ambient temperature for continuous operation?

The BC817-25W supports ambient temperatures from −65 °C to +150 °C per its storage and operating specification. For continuous DC operation at full 500 mA I_C, ambient must remain ≤100 °C when mounted on standard FR4 with single-sided copper, based on thermal derating curves in Figure 1. At 125 °C ambient, maximum usable I_C drops to ~350 mA.

Can BC817-25W replace BC847B in existing designs?

No-BC847B is an SOT23-packaged NPN with h_FE = 200–450 but rated for only 100 mA I_C and 50 V V_CEO. While pin-compatible, BC817-25W's 500 mA rating and SOT323 footprint require PCB land pattern revision. Its higher current capability makes it unsuitable as a drop-in replacement without layout and thermal validation.

Is BC817-25W qualified for automotive applications?

No-this part is explicitly non-automotive qualified per Nexperia's revision history (v.8, July 2022). It lacks AEC-Q101 qualification, automotive-grade screening, and extended temperature validation. For automotive use, Nexperia recommends the BC817-Q series variants, which undergo additional reliability testing and operate across −40 °C to +150 °C with guaranteed parametric stability.

How does thermal resistance change with PCB copper area?

R_th(j-a) improves from 625 K/W (standard footprint) to 431 K/W when the collector pad is expanded to 1 cm² on FR4, per Table 7. This 31 % reduction lowers junction temperature rise by ~58 °C at 500 mA, directly extending lifetime and enabling higher duty cycles in thermally constrained enclosures.