onsemi BC847BLT1

Overview

BC847BLT1 from onsemi is an NPN general-purpose silicon transistor in SOT-23 package, rated for 45 V_CEO, 100 mA continuous collector current, and 225 mW power dissipation at 25°C. It delivers DC current gain (h_FE) of 200–450 at I_C = 2.0 mA, V_CE = 5.0 V, and supports switching and amplification in low-voltage signal conditioning circuits.

For engineers reviewing the BC847BLT1 datasheet, pinout, applications, or equivalent options, key selection criteria include its AEC-Q101 qualification, moisture sensitivity level 1, ESD robustness (>4000 V HBM), and verified performance across −55°C to +150°C junction temperature range.

Technical Context

This device operates as a discrete NPN bipolar junction transistor optimized for linear amplification and digital switching. Its base-emitter turn-on voltage is 580–700 mV at I_C = 2.0 mA, and saturation voltage is ≤0.25 V at I_C = 10 mA / I_B = 0.5 mA - enabling efficient low-power logic interfacing.

The BC847BLT1 exhibits f_T = 100 MHz at I_C = 10 mA, V_CE = 5.0 V, supporting RF-coupled pre-amplifier stages and high-speed switching up to ~10 MHz. Output capacitance C_obo is 4.5 pF at V_CB = 10 V, limiting high-frequency loading in impedance-matched paths.

Key Specifications

Pinout & Package

SOT-23 (TO-236) surface-mount package: 2.90 mm × 1.30 mm × 1.00 mm body, 1.90 mm lead pitch, JEDEC-compliant footprint with thermal pad not required.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC847BLT1, BC847B,115 offers higher thermal power margin but lacks automotive qualification, while MMBT3904LT1G trades voltage rating for superior RF performance - making BC847BLT1 optimal for cost-sensitive, temperature-stressed 24 V switching where moderate bandwidth suffices.

Availability

BC847BLT1 is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor signal conditioning, and consumer LED lighting requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for BC847BLT1 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

onsemi is a global semiconductor supplier delivering energy-efficient power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The BC847BLT1 belongs to onsemi's BC846ALT1G Series of general-purpose NPN transistors designed for high-reliability signal switching and amplification in space-constrained, thermally demanding environments.

FAQ

What is the maximum operating temperature for BC847BLT1?

The BC847BLT1 has a junction and storage temperature range of −55°C to +150°C. This allows uninterrupted operation in under-hood automotive locations and industrial enclosures without thermal derating below 150°C ambient, provided PCB thermal design maintains junction temperature within limit. The BC847BLT1 datasheet specifies thermal resistance R_JA = 556°C/W on FR-5 board.

Is BC847BLT1 pin-compatible with BC847B,115?

Yes, BC847BLT1 and BC847B,115 share identical SOT-23 pinout (pin 1 = base, pin 2 = emitter, pin 3 = collector) and mechanical footprint. However, BC847BLT1 is AEC-Q101 qualified and rated for 225 mW PD, whereas BC847B,115 is rated for 250 mW PD but lacks automotive qualification - direct substitution requires validation of reliability requirements.

Does BC847BLT1 support 5 V logic-level drive?

Yes, BC847BLT1 reliably saturates with 5 V TTL or CMOS logic driving the base through a current-limiting resistor. At I_C = 10 mA and I_B = 0.5 mA, V_BE(sat) is ≤0.9 V and V_CE(sat) ≤0.25 V, confirming full turn-on. For 3.3 V MCU GPIO, a 2.2 kΩ base resistor achieves ~1.2 mA I_B, ensuring robust saturation across process and temperature variation.

What is the typical noise figure of BC847BLT1 in audio preamplifier use?

The BC847BLT1 exhibits a noise figure of ≤10 dB at I_C = 0.2 mA, V_CE = 5.0 V, R_S = 2.0 kΩ, f = 1.0 kHz, and BW = 200 Hz. This makes it suitable for low-noise microphone preamplifiers and sensor signal conditioning where sub-10 dB NF is required - though dedicated low-noise transistors may offer further improvement below 4 dB.

Can BC847BLT1 be used in linear regulator pass transistor applications?

No, BC847BLT1 is not recommended as a pass transistor in linear regulators due to its limited power dissipation (225 mW on FR-5 board) and lack of Safe Operating Area (SOA) characterization for sustained linear-mode operation. Its SOA curves in the datasheet are defined only for pulsed conditions. For linear regulation, purpose-built pass transistors with higher PD, SOA-rated operation, and thermal shutdown are preferred.