NXP Semiconductors BC557B,116

Overview

BC557B,116 from NXP Semiconductors is a PNP general-purpose bipolar junction transistor in TO-92 (SOT54) package, rated for −45 V V_CEO, −100 mA I_C, and 500 mW P_tot, with h_FE of 220–475 at I_C = −2 mA, used in low-voltage switching and linear amplification circuits.

For engineers reviewing the BC557B,116 datasheet, BC557B,116 pinout, BC557B,116 application, or BC557B,116 equivalent, key selection criteria include its PNP polarity, TO-92 mechanical compatibility, DC current gain range, saturation voltage performance at −10 mA/−0.5 mA bias, and thermal resistance of 250 K/W on FR4 PCB.

Technical Context

The BC557B,116 operates as a silicon PNP BJT with fixed emitter-base and collector-base junctions optimized for general-purpose analog and digital signal handling below 100 MHz. Its f_T of 100 MHz and low C_c (3 pF) support moderate-frequency amplification while maintaining stable h_FE across −1 mA to −100 mA collector currents.

Designed for through-hole mounting on standard FR4 boards, it features V_BE = −650 mV typical at I_C = −2 mA and exhibits predictable thermal drift: V_BE decreases by −2 mV/K, enabling basic temperature-compensated biasing in discrete amplifier stages.

Key Specifications

Pinout & Package

BC557B,116 is housed in a plastic single-ended leaded (through-hole) TO-92 package, also designated SOT54 or SC-43A, with 3 leads spaced at 2.54 mm pitch and overall dimensions of 4.8 × 4.2 × 14.5 mm (D × E × L).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC557C,116 and PN2907A, the BC557B,116 offers balanced h_FE consistency (220–475) and proven thermal behavior on FR4, making it optimal for cost-sensitive, medium-speed switching and amplification where predictable bias and manufacturability are prioritized over extreme gain or voltage headroom.

Availability

BC557B,116 is available at Aetrix Electronics and suitable for LED driver circuits, relay interface modules, audio pre-amplifier stages, and level-shifting interfaces requiring stable component supply and long-term production continuity.

Supply support for BC557B,116 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer applications.

The BC557B,116 belongs to NXP's legacy general-purpose bipolar transistor product line, designed specifically for cost-effective, reliable discrete signal switching and amplification in through-hole assembled equipment.

FAQ

What is the maximum collector-emitter voltage rating for BC557B,116?

The BC557B,116 has a maximum collector-emitter voltage (V_CEO) rating of −45 V under open-base conditions, as specified in the Absolute Maximum Ratings table of the NXP product data sheet dated 2004 Oct 11. This value defines the upper limit for safe DC operation in common-emitter configurations and must not be exceeded to prevent junction breakdown. Derating is recommended above +25 °C ambient.

Does BC557B,116 have a specified transition frequency (f_T)?

Yes, the BC557B,116 has a specified transition frequency (f_T) of 100 MHz, measured at V_CE = −5 V, I_C = −10 mA, and f = 100 MHz. This parameter confirms its suitability for audio-frequency amplification and low-speed switching applications but does not guarantee stable operation beyond 10–20 MHz in practical circuits due to layout-dependent parasitics and gain roll-off.

What is the thermal resistance (R_th(j-a)) of BC557B,116 on FR4 PCB?

The thermal resistance from junction to ambient (R_th(j-a)) for BC557B,116 is 250 K/W when mounted on a standard FR4 printed-circuit board, as stated in the Thermal Characteristics section. This value assumes no copper pour or heatsinking and directly determines the maximum power dissipation allowed at a given ambient temperature-e.g., 300 mW at +50 °C ambient.

How does the h_FE range of BC557B,116 compare to BC556B?

The BC557B,116 has an h_FE range of 220–475 at I_C = −2 mA, identical to BC556B per the NXP datasheet. However, BC556B is rated for −65 V V_CEO versus −45 V for BC557B,116, making BC556B preferable in higher-voltage PNP switching roles while maintaining matching gain behavior in shared design platforms.

Is BC557B,116 pin-compatible with BC557C,116?

Yes, BC557B,116 is pin-compatible with BC557C,116-they share identical TO-92 (SOT54) packaging, pinout (emitter-base-collector on leads 1-2-3), and mechanical dimensions. The only functional difference is h_FE: BC557C,116 is binned to 420–800, whereas BC557B,116 is 220–475. No PCB changes are required when substituting between these variants.