Infineon BF999E6327 Dual N-Channel MOSFET: Datasheet, Application Circuit, and Replacement Guide
The Infineon BF999E6327 is a high-performance dual N-channel enhancement mode MOSFET housed in a compact SOT-363 (SC-88) package. It is specifically engineered for high-frequency, low-power applications, making it a cornerstone component in RF circuits and VHF/UHF amplifiers. This article provides a detailed overview of its key specifications, a typical application circuit, and guidance for finding a suitable replacement.
Datasheet Overview and Key Specifications
The BF999E6327 integrates two independent, electrically isolated N-channel MOSFETs on a single silicon chip. This dual configuration is ideal for differential amplifier designs and space-constrained applications. Its primary appeal lies in its excellent high-frequency characteristics.
Key parameters from the datasheet include:
Drain-Source Voltage (VDS): 20 V
Gate-Source Voltage (VGS): ±12 V
Continuous Drain Current (ID): 20 mA per transistor
Total Power Dissipation (Ptot): 300 mW
On-State Resistance (RDS(on)): Typically 12 Ω (at I<�> = 5 mA, VGS = 10 V)
Critical High-Frequency Parameters: Low feedback capacitance (Crss < 0.25 pF) and high transition frequency (fT > 600 MHz) are crucial for minimizing signal loss and ensuring stable amplification at very high frequencies.
Typical Application Circuit
The most common application for the BF999E6327 is in cascode amplifier circuits for VHF and UHF tuners, such as those found in television and radio receivers. The cascode configuration, which uses one transistor in a common-source mode and the second in a common-gate mode, offers high gain, excellent input-output isolation, and broad bandwidth.
A simple cascode RF amplifier circuit is shown below:
```
Vdd
|
Rload
|
|----Output
|
| (Q2 - Common Gate)
|
| (Q1 - Common Source)
|
Input---
