BF422 transistor
BF422 transistor electrical specification
- BF422 is an NPN silicon epitaxial HIGH voltage transistor device
- Collector to emitter voltage (VCE) is 250V
- Collector to base voltage (VCB) is 250V
- Emitter to base voltage (VEB) is 5V
- Collector current is 50mA
- Pulsed collector current is 100mA
- Power dissipation is 830W
- DC current gain is 50hFE
- Junction temperature is between -55 to 150℃
- Thermal resistance is between, junction to ambient 150℃/W
- Collector to emitter saturation voltage (VCE (SAT)) is6V
- Transition frequency is 60MHz
- Low feedback capacitance
BF422 PINOUT
| Pin Number | Pin Name | Description |
| 1 | Emitter | Current flows through the emitter |
| 2 | Collector | Current flow through the collector |
| 3 | Base | The base terminal is used to trigger the transistor |
BF422 package
BF422 HIGH voltage transistor has a TO-92 package, it is a three-terminal small-sized device package.
TO-92 is a through-hole package made with epoxy/plastic material which will provide higher temperature capacity and compactness as an electronic component.
BF422 is a high-voltage device, so power handling ability is needed for these kinds of devices.
BF422 transistor specification description/ application note:
Here in this section, we explain the different electrical specifications of the BF422 JFET transistor, this clear explanation is really helpful for a better understanding of the device for the replacement process.
Voltage specs
The voltage specifications of the BF422 transistor are a collector-to-emitter voltage is 250V, a collector-to-base voltage is 250V, and an emitter-to-base voltage is 5V.
The collector-to-emitter saturation voltage is 0.6V, it is the switching voltage value of the device.
Overall BF422 is a high-voltage transistor mainly used for applications such as power supply and heavy types of equipment.
Current specs
The collector current value of the BF422 transistor is 50Ma, the current value is the maximum load capacity of the device.
The pulsed collector current value of the BF422 transistor is 100Ma, this value is calculated at a specific condition
The current value is important for switching and also for different equipment applications.
Dissipation specs
The dissipation ability of the BF422 transistor is 830Mw, this value is mainly dependent on the device package.
Current gain specs
The DC current gain value of the BF422 transistor is 50Hfe, this value is important for amplification and equipment applications.
Maximum temperature
The maximum temperature value of the BF422 transistor is -55 to +150℃.
Thermal resistance
The thermal resistance value of the BF422 transistor is 150℃/W
Transition frequency
The frequency value of the BF422 transistor is 60MHz, this value is important at the circuit level.
BF422 DATASHEET
If you need the datasheet in pdf please click this link
BF422 equivalent
BF422 HIGH voltage transistor device has equivalent devices such as ZTX457, STX0560, BF420, KSC2330Y, 2SC1473AQ, 2SC3941-R, 2SC3468-E, 2SC2271-E, and KSC1506-O, each of them had the same set of electrical specifications.
BF422 transistors had high voltage circuit applications, so, during the replacement process, we need to check and verify specs such as voltage, current, and PINOUT details because it is very dangerous at the circuit level.
BF422 complementary
BF422 NPN transistors have complementary transistor BF423 PNP transistors, each of them having the same set of electrical specifications.
BF422 SMD equivalent
The SMD transistor such as BF620 (SOT-89), BF820 (SOT-23), and BF822 (SOT-23), are the SMD equivalent of BF422 transistors.
BF422 vs ZTX457
In the table below, we listed and compare the electrical specifications of BF422 and ZTX457, this comparison is really useful for a better understanding of the device.
Characteristics BF422 ZTX457
Collector to emitter voltage (VCE) 250V 300V
Collector to base voltage (VCB) 250V 300V
Emitter to base voltage (VEB) 5V 5V
Collector to emitter saturation voltage (VCE (SAT)) 0.6V 0.3V
Collector current (IC) 50mA 500mA
Pulsed collector current (ICM) 100mA 1A
Power dissipation 830W 1W
Junction temperature (TJ) -55 to +150°C -55 to +200°C
Transition frequency (FT) 60MHz 75MHz
Gain (hFE) 50hFE 25 to 300hFE
Package TO-92 TO-92
BF422 applications
- Class B video output stage in color television and professional monitor equipment
- Switching circuit
- High voltage general purpose applications
Graphical characteristics curves of BF422
The figure shows the DC current gain characteristics of the BF422 high voltage transistor, the graph plots with DC current gain vs collector current.
At constant collector-to-emitter voltage values, the curves are been plotted at three different temperature values, the DC gain value increases constantly and dips at the end with respect to the collector current.
