onsemi SBCW72LT1

Overview

SBCW72LT1 from ON Semiconductor is an NPN silicon general-purpose transistor in SOT-23 package, rated for 45 V_CEO, 100 mA continuous collector current, and DC current gain (h_FE) of 200–450 at I_C = 2 mA / V_CE = 5 V. It serves as a low-power switching or amplification element in signal conditioning, biasing, and interface circuits across consumer and industrial electronics.

For engineers reviewing the SBCW72LT1 datasheet, pinout, applications, or equivalent options, key selection criteria include its 300 MHz f_T, low V_CE(sat) (0.21 V @ 10 mA/0.5 mA), 4.0 pF C_obo, thermal resistance of 556 °C/W on FR-5 board, and Pb-free SOT-23 packaging compliant with RoHS requirements.

Technical Context

The SBCW72LT1 operates as a discrete bipolar junction transistor with fixed NPN polarity, optimized for linear amplification and saturated switching in low-voltage, low-current analog and digital interface stages. Its design supports stable h_FE across −55°C to +150°C junction temperature range and exhibits predictable noise performance (NF ≤ 10 dB @ 1 kHz, I_C = 0.2 mA).

Thermal behavior is characterized by two dissipation modes: 225 mW on FR-5 board (derated 1.8 mW/°C above 25°C) and 300 mW on alumina substrate (derated 2.4 mW/°C), enabling flexible PCB material selection based on thermal budget constraints.

Key Specifications

Pinout & Package

SBCW72LT1 is housed in a surface-mount SOT-23 (TO-236) package per CASE 318, STYLE 6, with 3 terminals and footprint dimensions of 2.90 mm × 1.30 mm × 0.95 mm (L × W × H). The package is Pb-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SBCW72LT1, BC847BT offers broader h_FE range and BC847BT's higher C_ibo may affect high-frequency stability, while MMBT3904LT1G delivers superior switching speed and lower saturation loss but requires validation of SOA under pulsed loads.

Availability

SBCW72LT1 is available at Aetrix Electronics and suitable for audio signal amplification, logic-level interface buffering, LED driving, and current mirror reference applications requiring stable component supply, long-term manufacturability, and RoHS-compliant sourcing.

Supply support for SBCW72LT1 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The SBCW72LT1 belongs to ON Semiconductor's general-purpose bipolar transistor product line, designed for cost-sensitive, space-constrained applications requiring reliable low-power amplification and switching in commercial and industrial environments.

FAQ

What is the maximum junction temperature rating for the SBCW72LT1?

The SBCW72LT1 has a specified junction and storage temperature range of −55°C to +150°C. This allows operation in harsh thermal environments such as automotive under-hood modules or industrial motor controls. Derating curves in the datasheet define safe power dissipation limits above 25°C ambient, with thermal resistance R_JA = 556 °C/W on FR-5 board. Always verify actual T_J using measured case temperature and power dissipation in final layout.

Does the SBCW72LT1 support Pb-free soldering processes?

Yes, the SBCW72LT1 is offered in a Pb-free SOT-23 package compliant with RoHS Directive 2011/65/EU. Its marking includes "M" for date code and no lead content, and it supports standard reflow profiles per J-STD-020. ON Semiconductor provides detailed soldering guidelines in their Soldering and Mounting Techniques Reference Manual (SOLDERRM/D) for optimal wetting and intermetallic formation.

What is the typical noise figure of the SBCW72LT1 and under what conditions is it measured?

The SBCW72LT1 has a maximum noise figure (NF) of 10 dB, measured 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 value reflects its suitability for low-noise preamplifier stages in sensor interfaces. Noise performance degrades at higher currents or frequencies-designers should consult Figures 3–7 in the datasheet for en and In spectral density curves across bias and source impedance.

Can the SBCW72LT1 be used in switching applications, and what are its key timing parameters?

Yes, the SBCW72LT1 is qualified for switching use with documented turn-on time (t_d + t_r) and turn-off time (t_s + t_f) in Figures 1 and 2. At I_C/I_B = 10, V_CC = 3.0 V, and T_J = 25°C, typical total switching time is under 300 ns. Its low V_CE(sat) (0.21 V) and moderate f_T (300 MHz) make it appropriate for sub-10 MHz digital buffering and PWM-driven LED or relay control, provided SOA limits are respected during transients.

How does the SBCW72LT1's h_FE vary with temperature and collector current?

The SBCW72LT1's h_FE decreases with rising temperature above 25°C and shows nonlinearity at low I_C (<0.1 mA) and high I_C (>50 mA), as shown in Figure 8. At I_C = 2 mA and V_CE = 5 V, h_FE ranges from ~200 at −55°C to ~350 at 25°C to ~250 at 125°C. Designers should use worst-case h_FE min (200) for saturation calculations and derate base drive accordingly in thermally demanding applications.