Nexperia USA Inc. BC857BS-QX

Overview

BC857BS-QX from Nexperia is a dual PNP general-purpose transistor in SOT363-3 (SC-88) package, delivering matched h_FE (200–450), low V_CEsat (−400 mV at −100 mA/−5 mA), and AEC-Q101 qualification for automotive signal switching. It integrates two isolated PNP transistors with no mutual interference, enabling compact dual-channel biasing or complementary pair use with BC847BS-Q in space-constrained PCBs.

For engineers reviewing the BC857BS-QX datasheet, BC857BS-QX pinout, BC857BS-QX application, or BC857BS-QX equivalent, this page provides verified pin functions, thermal derating curves, per-transistor limiting values (V_CEO = −45 V, I_C = −100 mA), and automotive-grade reliability context - critical for ECU input conditioning, LED driver current mirroring, and dual-sensor interface designs.

Technical Context

This dual PNP device operates with independent emitter-base and collector-emitter junctions per transistor, supporting discrete current mirror, differential pair, or redundant switching topologies. Each transistor exhibits tightly matched DC current gain (h_FE) across 200–450 at V_CE = −5 V and I_C = −2 mA, with low base-emitter saturation voltage (−755 mV typical at I_C = −10 mA/I_B = −0.5 mA).

Thermal performance is defined for both per-transistor (R_th(j-a) = 568 K/W) and per-device (R_th(j-a) = 416 K/W) operation on FR4 PCBs. Its 2.2 pF collector capacitance and 100 MHz f_T support stable operation up to mid-frequency analog switching without oscillation risk.

Key Specifications

Pinout & Package

SOT363-3 (SC-88/TSSOP6) plastic surface-mount package with 0.65 mm lead pitch, 2.2 mm × 1.35 mm body, and transparent top view marking. Designed for reflow soldering with standard footprint (2.65 mm × 1.3 mm land pattern).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual PNP transistor applications.

Compared with BC857BDS-Q, BC857BS-Q offers direct pin compatibility with existing SOT363-3 layouts; versus MBT3906DW1T1G, it delivers superior gain matching and automotive qualification-critical for functional safety compliance in ASIL-B systems.

Availability

BC857BS-QX is available at Aetrix Electronics and suitable for automotive ECU signal conditioning, industrial sensor interface boards, and medical infusion pump motor drivers requiring stable component supply across extended product lifecycles.

Supply support for BC857BS-QX 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 leadership in automotive-qualified components and advanced packaging.

BC857BS-QX belongs to Nexperia's AEC-Q101-qualified general-purpose transistor family, engineered for robustness in automotive signal switching, sensor interfacing, and power management where space, thermal efficiency, and long-term reliability are critical.

FAQ

Is BC857BS-QX pin-compatible with BC847BS-Q?

No - BC857BS-QX is a dual PNP transistor while BC847BS-Q is its NPN complement; they share the same SOT363-3 package and pin count but have opposite polarity and inverted pin functions (e.g., Pin 1 is E1 in BC857BS-QX but C1 in BC847BS-Q). They are designed for complementary pairing, not pin-for-pin substitution.

What is the maximum allowable junction temperature during pulsed operation?

The absolute maximum junction temperature is 150 °C under all conditions, including pulsed operation. For transient pulses (tp ≤ 1 ms), thermal impedance data (Fig. 2) shows Z_th(j-a) ≈ 230 K/W at 0.1 duty cycle, meaning a 100 mA pulse at −400 mV V_CEsat generates ~40 mW average power - well within safe limits if ambient stays below 125 °C.

Can BC857BS-QX be used in linear amplifier configurations?

Yes - its specified h_FE linearity (Fig. 3), low noise figure (2 dB at 1 kHz), and stable V_BE (−655 mV typical) support Class-A small-signal amplification. However, its 300 mW per-device power limit restricts use to low-power stages; thermal derating must be applied above 25 °C ambient.

Does the "-Q" suffix guarantee automotive qualification?

Yes - the "-Q" suffix per Nexperia's naming convention explicitly denotes AEC-Q101 qualification. This includes stress testing for temperature cycling, humidity bias, HTRB, and ESD (HBM ≥ 2 kV), with full test reports available upon request for PPAP submission in automotive programs.