onsemi BC557_D11Z

Overview

BC557_D11Z from onsemi is a PNP epitaxial silicon transistor designed for general-purpose switching and amplification in low-to-medium power analog and digital circuits. It features V_CEO = −45 V, I_C = −100 mA, h_FE = 110–800 (Class A/B/C), V_CE(sat) ≤ −300 mV at I_C = −10 mA/I_B = −0.5 mA, and f_T = 150 MHz - enabling use in audio preamplifiers, level shifters, and discrete logic interfaces.

For engineers reviewing the BC557_D11Z datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, TO-92-3 package compatibility, guaranteed h_FE classification per marking (e.g., "D11Z" indicating Class B), low-noise performance at 200 µA bias, and RoHS-compliant Pb-free construction.

Technical Context

The BC557_D11Z operates as a medium-voltage, medium-current PNP bipolar junction transistor with complementary pairing to NPN BC547/BC548 series. Its design supports linear amplification (V_CE ≥ −5 V, I_C ≤ −10 mA) and saturated switching (V_CE(sat) ≤ −300 mV) across −55 °C to +150 °C ambient range.

Thermal performance is defined by R_JA = 250 °C/W on standard FR-4 PCB (76 mm × 114 mm), with 4.0 mW/°C derating above 25 °C and 500 mW maximum dissipation. Noise figure is specified at 2–10 dB (1 kHz, I_C = −200 µA, R_G = 2 kΩ), confirming suitability for low-noise preamp stages.

Key Specifications

Pinout & Package

BC557_D11Z is housed in TO-92-3 plastic package (Case 135AR), with standardized leadform: flat side facing viewer, leads down, pin 1 (Collector) left, pin 2 (Base) center, pin 3 (Emitter) right.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC557BTA and BC557BTF, BC557_D11Z offers identical transistor performance and reliability but differs only in packaging format and marking convention - making it functionally interchangeable in all circuit implementations where TO-92-3 mechanical fit is maintained.

Availability

BC557_D11Z is available at Aetrix Electronics and suitable for audio preamplifiers, discrete logic level shifters, and LED driver switches requiring stable component supply, consistent h_FE binning, and RoHS-compliant manufacturing.

Supply support for BC557_D11Z 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 (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The BC557_D11Z belongs to onsemi's legacy general-purpose bipolar transistor family, engineered for cost-sensitive, high-reliability discrete analog functions including amplification, switching, and signal conditioning in consumer and industrial electronics.

FAQ

What is the h_FE classification for BC557_D11Z?

The "D11Z" suffix indicates BC557_D11Z is a Class B transistor, with DC current gain (h_FE) ranging from 200 to 450 when measured at V_CE = −5 V and I_C = −2 mA. This classification is confirmed in the onsemi datasheet's h_FE Classification table and ensures predictable base drive requirements in amplifier and switch designs using BC557_D11Z.

Is BC557_D11Z pin-compatible with BC547 series NPN transistors?

Yes - BC557_D11Z uses the same TO-92-3 package (Case 135AR) and pinout (C-B-E) as BC547/BC548 NPN devices, enabling direct physical placement in complementary circuits. However, polarity reversal must be accounted for in schematic design and PCB layout when substituting BC557_D11Z for an NPN device in the same footprint.

What is the maximum operating temperature for BC557_D11Z?

BC557_D11Z has a maximum junction temperature (T_J) of 150 °C and a storage temperature range of −65 °C to +150 °C. When operated at full 500 mW dissipation, ambient temperature must remain ≤25 °C; derating to 4.0 mW/°C applies above that point, allowing BC557_D11Z to sustain operation up to +125 °C ambient in typical PCB layouts.

Does BC557_D11Z meet RoHS and REACH requirements?

Yes - BC557_D11Z is explicitly stated in the onsemi datasheet as Pb-free, halogen-free/BFR-free, and RoHS compliant per Directive 2011/65/EU. It also satisfies REACH SVHC screening requirements, with full material declarations available through onsemi's compliance portal for BC557_D11Z.

Can BC557_D11Z replace BC558 in a circuit?

No - BC557_D11Z and BC558 differ in key ratings: BC557_D11Z has V_CEO = −45 V and V_CBO = −50 V, while BC558 specifies V_CEO = −30 V and V_CBO = −30 V. Substituting BC557_D11Z for BC558 may be acceptable in low-voltage circuits (<25 V), but violates absolute maximum ratings in higher-voltage applications; always verify voltage margins before replacement in existing BC558 designs.