BF199 transistor

BF199 transistor
BF199 transistor

BF199 transistor electrical specification

  • BF199 is an NPN silicon planer epitaxial RF amplifier transistor device
  • Collector to emitter voltage (VCE) is 25V
  • Collector to base voltage (VCB) is 40V
  • Emitter to base voltage (VEB) is 4V
  • Collector current is 50mA
  • Power dissipation is 350W
  • DC current gain is 38 to 40hFE
  • Junction temperature is between -55 to 150℃
  • Collector to emitter saturation voltage (VCE (SAT)) is2V
  • Transition frequency is 400MHz
  • Noise figure value is 5dB
  • Low current
  • Low voltage


Pin Number Pin Name Description
1 Collector Current flow through the collector 
2 Emitter  Current flows through the emitter
3 Base Base terminal is used to trigger the device


BF199 package

The BF199 is an RF amplifier device which had a TO-92 transistor package, it is a general-purpose device package.

TO-92 package had a particular shape and size apt for small-scale circuit applications, it is made with epoxy/plastic material, and this will increase the temperature capacity with a compact package.

BF199 transistor specification description/ application note:

In this section we explain the electrical specification of the BF199 transistor, this explanation is really useful for a better understanding of the device mainly for the replacement process.

Voltage specs

The terminal voltage value of the BF199 transistor are collector-to-emitter voltage is 25V, collector-to-base voltage is 40V, and emitter-to-base voltage is 4V, the voltage values indicate this device has low voltage specs, so applications based on this device is mostly general purpose.

The collector-to-emitter saturation voltage value is 0.2V, this value is important for the switching of the transistor.

Current specs

The collector current value of the BF199 transistor is 50mA, and the current value is the load capacity of the device.

The applications like switching and driving have an important role in current specs, so BF199 transistors have low values at load capacity.

Dissipation specs

The power dissipation value of the BF199 transistor is 350Mw, this value is calculated by adding the voltage value and current value of the device.

Current gain specs

The DC current gain value of the BF199 transistor is 38 to 40Hfe, this gain value is important for the application circuit like the amplifier and power supply.

Maximum temperature

The junction temperature and storage temperature value of the BF199 transistor is -55 to +150℃.

Thermal resistance

The thermal resistance between, the junction and the case of the BF199 transistor is 125℃/W.

Transition frequency 

The transition frequency value is important at the circuit level, which is 400MHz, this is also important at some circuits.

Noise figure

The noise figure value of the BF199 transistor is 2.5Db.


If you need the datasheet in pdf please click this link

BF199 equivalent

BF199 RF amplifier transistor has equivalent transistor devices such as 2N9018, C3355, BF197P, BF198, BC639, BF200, BF206, BF209, and BF244, each of them had almost the same electrical specification which is more comfortable for the BF199 replacement process.

BF199 transistors have more audio-related applications, so specs such as voltage, current, frequency, and saturation voltage had more importance, so check and verify such specs at each device.

BF199 complementary

BF199 transistor does not have a specific complementary transistor that has the same and opposite specifications.

BF199 vs BC639

In this table we listed the electrical specifications of BF199 and BC639 transistors, this comparison chart is very useful for a better understanding of the device.

Collector to emitter voltage (VCE)      25V     80V
Collector to base voltage (VCB)40V80V
Emitter to base voltage (VEB)4V5V
Collector to emitter saturation voltage (VCE (SAT))0.2V0.5V
Collector current (IC)50mA1A
Power dissipation350W625mW
Junction temperature (TJ)-55 to +150°C-55 to +150°C
Thermal resistance125℃/W200℃/W
Transition frequency (FT)   400MHz200MHz
Gain (hFE)38 to 40hFE40 to 160hFE
Noise figure2.5dB-

BF199 FM radio transmitter circuit

BF199 FM radio transmitter circuit
BF199 FM radio transmitter circuit

The figure shows the BF199 transistor-based FM radio transmitter circuit, the circuit consists of two BF199 transistors as active components and a few passive components.

BF199 applications

  • The output stage of a vision AF amplifier
  • FM receiver applications
  • FM sender circuit
  • Audio amplifier circuit
  • Preamp circuit
  • RF mixer circuit
  • FM/AM radio circuit
  • RF switching
  • RF signal generator
  • High-frequency applications

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *