Ultra-Low Noise, Audio, N-Channel JFE150 JFET
the specifications of n-channel JFE150 JFET
- JFET150 is an n-channel JFET transistor device
- Drain to source voltage (VDS) is -40V to 40V
- Gate to source, the gate to drain voltage is -40V to 0.9V
- VVCH Voltage between VCH to D, G, or S is 40V
- VVCL Voltage between VCL to D, G, or S is -40V
- Drain to source current (IDSS) is -20 to 20mA
- (IVCL) and (IVCH) current is 20mA
- Gate to source breakdown voltage (VGSS) is -40V
- Gate to source cut-off voltage (VGSC) is -1.5V to 0.9V
- Gate to source voltage (VGS) is -0.9V to -0.5V
- Low input capacitance is 24pF at VDS= 5V
- Junction temperature is (TJ)-55 to 150°C
- Voltage noise: 8nV/√Hz at 1 kHz, IDS= 5mA
0.9nV/√Hz at 1 kHz, IDS= 2mA
- Current noise: 8fA/√Hz at 1 kHz
the pin configuration and package details about JFE150 JFET
| Pin Number | Pin Name | Description |
| 1 | VCH | Positive diode clamp voltage |
| 2 | VCL | Negative diode clamp voltage |
| 3 | GATE | Gate terminal is used to trigger the device |
| 4 | SOURCE | Current flows through the source terminal |
| 5 | DRAIN | Current flows through the drain terminal |
The JFE150 JFET transistor had 5 terminal devices, so drain, source, and gate are the common pins for all JFET transistors, but at JFE150 transistor VCH and VCL are the extra device terminals.
The JFE150 is known as the ultra-low noise JFET device, the negative and positive clamp diode (VCH and VCL) are the component used to reduce the noise figure of the device.
The JFE150 JFETs are the most sensitive audio component, so the package used for it is smallSC70 and they are also available at surface-mount packages such as SOT-23.
the internal functional diagram of JFE150 JFET transistor
The figure shows the functional block diagram of the JFE150 JFET transistor, the blocks consist of a JFET transistor with negative and positive clamp diodes on each of the devices.
The integrated with diodes to separate clamp nodes to protect without the addition of high leakage, non-linear external diodes.
The JFE150 diodes are used to help clamp voltage surges that occur on the sensor to the gate, the diodes connected between the gate and two separate pins VCL and VCH.
The clamping mechanism works by steering current from the gate into the VCL or VCH nodes when the voltage at the gate is less than VCL or greater than VCH.
the Brief explanation and Description of JFE150
The JFE150 JFET transistor is popular for its ultra-low noise performance as the audio application component, it had a high gate to drain and gate to the source breakdown voltage of -40v.
The drain to source current offered by JFE150 is -20 to 20Ma and also it had a very low gate current.
The drain to source at JFE150 is -40V to 40V, the gate to source voltage is -0.9V to -0.5V.
The voltage between VVCL to D, G, or S is -40V, and the voltage between VVCH to D, G, or S is 40V.
The quiescent current is set by the user, and also yields excellent noise performance for currents 50uA to 20mA.
The voltage noise figure of JFE150 is 0.8nV/√Hz at 1 kHz; IDS= 5mA and 0.9nV/√Hz at 1 kHz; IDS= 2mA and the current noise figure of 1.8fA/√Hz at 1 kHz, the JFE150 transistor is a next-generation device to implement low noise amplifier for piezoelectric sensors, transducer, large area condenser microphones and hydrophones in small packages.
JFE150 JFET transistor datasheet
If you need the datasheet in pdf please click this link
the applications of JFE150 transistor
- Microphones inputs
- Hydrophones and marine equipment’s
- DJ controller, mixer, and other DJ equipment’s
- Guitar amplifier and other music instruments amplifiers
- Condition monitoring sensors
- Low noise design in audio
- SONAR
- Vibration analysis
JFE150 characteristics curves
The figure shows the drain to source current vs drain to source voltage curve, from the graphical itself we can see a proper 3stage working operation of the JFET transistor.
But other than that we can see each curve plotted in decrease order of gate to source voltage VGS, the current value increases when the gate voltage decreases.
The figure shows the input-referred noise density vs frequency graphical curve, we know the JFE150 is specially made for ultra-low-noise applications at most modern and advanced devices.
We can see different characteristics curves plots by the different drain to source current values, the curve shows that the noise figure at the JFE150 is increasing with a decrease in the drain to source current value.
Low noise, high impedance composite amplifier using JFE150
The composite amplifier using the JFE150 JFET transistor circuit in the figure above is capable to offer low noise with high output impedance and input impedance.
