Nexperia USA Inc. BC817K-40H-QR

Overview

BC817K-40H-Q from Nexperia is a 45 V, 500 mA NPN general-purpose transistor in SOT23 package, designed for automotive-grade switching and linear amplification with h_FE = 250–600 at V_CE = 1 V, I_C = 100 mA, and qualified to AEC-Q101. It operates reliably from −55 °C to +175 °C and delivers 700 mV V_CE(sat) at I_C = 500 mA / I_B = 50 mA.

For engineers reviewing the BC817K-40H-Q datasheet, BC817K-40H-Q pinout, BC817K-40H-Q application, or BC817K-40H-Q equivalent, this page provides verified thermal resistance (R_th(j-a) = 158–353 K/W), safe operating area curves, DC current gain vs. temperature, and automotive qualification evidence - all critical for high-reliability board-level design and BOM validation.

Technical Context

This NPN bipolar junction transistor uses epitaxial planar die construction with optimized doping profiles to sustain 45 V V_CEO and 1 A peak collector current (t_p ≤ 1 ms). Its base-emitter junction supports up to 7 V reverse bias, and collector-base breakdown reaches 50 V under open-emitter conditions.

The device exhibits strong h_FE stability across temperature (250–600 at 25 °C; >400 at 125 °C) and maintains low V_BE(sat) (≤1.2 V) and V_CE(sat) (≤700 mV) under rated DC and pulsed loads - enabling efficient drive in automotive body control modules and industrial sensor interfaces.

Key Specifications

Pinout & Package

SOT23 (TO-236AB) plastic surface-mount package with 3 leads, 1.3 mm profile, and standard footprint compatible with reflow and wave soldering per Nexperia's recommended land patterns (Fig. 44/45).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC817-40W and MMBT4401LT1G, BC817K-40H-Q uniquely combines AEC-Q101 qualification, 175 °C operation, and 250–600 h_FE in a single SOT23 device - making it the only drop-in solution for automotive body electronics requiring both reliability and precision gain control.

Availability

BC817K-40H-Q is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, and DC motor speed control circuits requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for BC817K-40H-Q 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 essential efficiency technologies, delivering high-performance, reliable discrete and logic devices for automotive, industrial, and consumer markets.

BC817K-40H-Q belongs to the BC817KH-Q series - a family of AEC-Q101-qualified general-purpose transistors engineered specifically for automotive signal switching, load driving, and analog amplification in harsh thermal environments.

FAQ

What is the maximum continuous collector current for BC817K-40H-Q at 100 °C ambient?

At T_amb = 100 °C, the maximum continuous collector current is derated to approximately 320 mA based on the 950 mW total power dissipation limit and thermal resistance curve for 4-layer PCB mounting (R_th(j-a) = 158 K/W). This ensures junction temperature remains below 175 °C under steady-state conditions.

Does BC817K-40H-Q support pulse operation beyond its DC ratings?

Yes - it supports 1 A peak collector current for pulses ≤1 ms (duty cycle ≤0.02), validated per IEC 60134 limiting values. The safe operating area (SOA) graph (Fig. 2) confirms stable operation at 1 A/10 V for 100 µs pulses, enabling use in short-duration inductive load switching.

How does the marking code %HF correspond to BC817K-40H-Q?

The marking code %HF appears on the top surface of the SOT23 package, where "%" is a placeholder for the manufacturing site code (e.g., "A" for Nijmegen), and "HF" unambiguously identifies the BC817K-40H-Q variant per Nexperia's ordering information table (Table 5).

Can BC817K-40H-Q replace BC817-40 in existing designs?

Yes - it is pin-compatible and electrically equivalent to BC817-40, but adds AEC-Q101 qualification, extended temperature range (−55 °C to +175 °C), and tighter h_FE binning (250–600 vs. 100–630). No layout changes are needed; qualification testing is recommended for automotive deployment.