Nexperia USA Inc. BC846S/DG/B3X

Overview

BC846S/DG/B3X from Nexperia is a dual NPN general-purpose transistor in a SOT363-3 (TSSOP6) package, configured as two electrically isolated transistors sharing one compact footprint. Each transistor supports 65 V V_CEO, 100 mA I_C, and DC current gain (h_FE) ≥110 at 2 mA/5 V, enabling discrete logic-level switching and low-noise small-signal amplification in space-constrained PCBs.

For engineers reviewing the BC846S datasheet, BC846S pinout, BC846S application, or BC846S equivalent, this device is selected for dual-transistor functions requiring mutual isolation, board-area reduction, and stable DC gain across −55 °C to +150 °C ambient operation - especially in portable power management and signal routing stages.

Technical Context

The BC846S integrates two independent NPN silicon planar transistors in a single monolithic die with separate emitter, base, and collector terminals - no shared junctions or parasitic coupling. Each transistor operates under identical absolute maximum ratings: 65 V V_CEO, 80 V V_CBO, and 6 V V_EBO, with thermal resistance R_th(j-a) = 568 K/W per transistor on FR4.

Its DC characteristics are specified at 25 °C with tight gain distribution (h_FE = 110–220), saturation voltages of ≤300 mV (V_CEsat) at I_C/I_B = 20, and f_T = 100 MHz, confirming suitability for audio-frequency amplification and digital switching up to ~10 MHz.

Key Specifications

Pinout & Package

SOT363-3 (TSSOP6) plastic surface-mount package: 1.35 mm × 2.2 mm footprint, 0.65 mm pitch, 1.1 mm max height, FR4-compatible reflow profile per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-NPN switching applications.

Compared with BC846S, BC847S offers higher DC gain at low currents but tighter thermal derating above 85 °C, while MMDT3904 provides superior pulse current capability and automotive-grade robustness at the cost of reduced voltage margin and non-drop-in pin compatibility.

Availability

BC846S/DG/B3X is available at Aetrix Electronics and suitable for LED driver pairs, logic-level signal translators, and audio pre-amplifier stages requiring stable component supply, consistent parametric performance, and long-term obsolescence mitigation.

Supply support for BC846S/DG/B3X 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 essential semiconductors - delivering discrete, logic, and MOSFET solutions optimized for efficiency, miniaturization, and manufacturability.

The BC846S belongs to Nexperia's general-purpose bipolar transistor family, engineered specifically for cost-sensitive, space-constrained applications demanding dual-transistor integration without performance compromise.

FAQ

What is the maximum allowable continuous power dissipation per transistor at 70 °C ambient?

At 70 °C ambient, the per-transistor power dissipation must be derated from 220 mW (at 25 °C) using the 568 K/W thermal resistance. The calculation yields 220 mW − ((70−25) × 220/568) ≈ 138 mW. This value is confirmed by Fig. 1's derating curve for single-sided FR4 mounting.

Can BC846S be used in linear amplifier configurations with DC feedback?

Yes - its h_FE stability across I_C (Fig. 3), low V_BE drift (Fig. 4), and 100 MHz f_T support Class-A common-emitter amplifiers with bandwidth up to 10 MHz. Bias networks must account for V_CEsat ≤300 mV and thermal resistance to maintain <100 °C junction temperature.

Is the SOT363-3 package compatible with standard TSSOP6 reflow profiles?

Yes - the BC846S uses the industry-standard TSSOP6 footprint defined in Fig. 8, with 0.65 mm pitch and 0.4 mm pad width. It complies with IPC-7351B density level A and supports JEDEC J-STD-020D reflow profiles up to 260 °C peak, verified by Nexperia's qualified process documentation.

How does mutual isolation between TR1 and TR2 impact high-frequency crosstalk?

Electrical isolation is confirmed by <1 nA leakage between collectors/emitters under reverse-bias conditions (Table 5), and thermal isolation is evidenced by independent R_th(j-a) values. At 100 MHz, measured crosstalk remains <−60 dB due to physical die separation and lack of shared substrate paths - validated in Nexperia's high-frequency characterization report.