NXP Semiconductors BF199,112

Overview

BF199,112 from NXP Semiconductors is an NPN medium-frequency transistor in TO-92 (SOT54/SC-43A) package, rated for V_CEO = 25 V, I_C = 25 mA, P_tot = 500 mW, h_FE ≥ 38 at 7 mA, and f_T = 550 MHz - designed for vision IF amplifier output stages.

For engineers reviewing the BF199,112 datasheet, BF199,112 pinout, BF199,112 application, or BF199,112 equivalent, key selection factors include its 550 MHz transition frequency, low-noise feedback capacitance (C_re ≤ 0.5 pF), and suitability for medium-frequency small-signal amplification with DC-coupled biasing.

Technical Context

The BF199,112 operates as a general-purpose NPN RF transistor optimized for frequencies up to ~100 MHz, with verified f_T = 550 MHz under V_CE = 10 V, I_C = 5 mA conditions. Its low C_re (≤ 0.5 pF) and moderate h_FE (38–100 range implied by typical gain curves) support stable high-gain IF amplification without oscillation.

Thermal resistance R_th(j-a) = 250 K/W on FR4 PCB enables reliable operation at ambient temperatures up to +150 °C when power dissipation remains within 500 mW limit. Absolute maximum ratings include V_CBO = 40 V and V_EBO = 4 V, confirming suitability for low-voltage video signal chain interfaces.

Key Specifications

Pinout & Package

BF199,112 is housed in a plastic through-hole TO-92 package (JEDEC TO-92, NXP SOT54 / SC-43A), with 3 leads and standard lead spacing (e = 2.54 mm). Mounting on FR4 PCB yields R_th(j-a) = 250 K/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN medium-frequency transistor applications.

Compared with BC548B and 2N3904, BF199,112 delivers superior medium-frequency gain-bandwidth product and lower feedback capacitance - making it the preferred choice where vision IF bandwidth, phase linearity, and oscillation immunity are design-critical.

Availability

BF199,112 is available at Aetrix Electronics and suitable for vision IF amplifiers, video distribution systems, low-voltage RF preamplifiers, and legacy CRT monitor video drivers requiring stable component supply and long-lifecycle support.

Supply support for BF199,112 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 BF199,112 belongs to NXP's legacy discrete RF transistor product line, engineered specifically for analog video signal processing in broadcast and display equipment operating in the 30–100 MHz IF band.

FAQ

What is the maximum operating frequency for BF199,112 in amplifier applications?

The BF199,112 has a transition frequency f_T of 550 MHz, but its practical small-signal amplification bandwidth is limited to approximately 100 MHz due to gain roll-off and stability constraints. In vision IF applications like PAL/NTSC (38.9 MHz), the BF199,112 maintains flat gain and low distortion - confirmed by NXP's characterization at 100 MHz test conditions. Always verify layout parasitics and load matching for optimal BF199,112 performance.

Is BF199,112 suitable for use in surface-mount designs?

No - BF199,112 is packaged exclusively in the through-hole TO-92 (SOT54/SC-43A) format and lacks an official SMD variant. Its leaded construction requires plated-through holes and wave soldering or hand assembly. For SMT alternatives, consider RF transistors such as MMBT5401 or PMBT3904, though these differ in f_T, C_re, and gain profile versus BF199,112.

What is the recommended bias configuration for BF199,112 in a vision IF amplifier?

NXP specifies BF199,112 for common-emitter operation with V_CE = 10 V and I_C = 7 mA (h_FE test condition). A stable bias uses emitter degeneration (e.g., 100 Ω resistor) and base voltage divider with bypassed emitter capacitor. Avoid direct base drive without current limiting - the BF199,112's V_EBO = 4 V limits reverse base-emitter stress. Thermal stability is enhanced by mounting BF199,112 on FR4 with adequate copper area.

Does BF199,112 meet RoHS compliance?

Yes - BF199,112 is RoHS-compliant per NXP's product status documentation and environmental declarations. The device contains no lead in solderable terminations and complies with EU Directive 2011/65/EU. NXP confirms RoHS compliance for BF199,112 in its official product change notifications and material declarations dated post-2006. Always verify lot-specific CoC when ordering for regulated production.

Can BF199,112 replace BF198 in existing designs?

BF199,112 and BF198 share identical TO-92 packaging and pinout, but BF199,112 offers higher f_T (550 MHz vs. 300 MHz for BF198) and tighter h_FE range. Electrical substitution is feasible in most vision IF stages, though BF199,112 may require minor compensation for increased gain and bandwidth. Review stability margins and adjust emitter degeneration if replacing BF198 with BF199,112 in production hardware.