Thursday, December 23, 2010
【 Weak current College 】 FET's main characteristic parameters 】
A, DC parameters
1. the clip UP fault voltage
The UDS as a fixed value of the ID is equal to a small current value (few µA), gate on the bias UGS is caught breaking voltage. It applies to the junction FET and exhausted-insulated gate field effect transistor.
2. turn on voltage at UT
The UDS as a fixed value of the S and D are formed between the conductive channel is open voltage UGS. It applies only to enhanced insulated gate field effect transistor.
3. the saturation current IDSS
In UDS-O, drain and the source is greater than the voltage between the clips off voltage of channel currents known as saturation current, it applies to the drain-insulated gate field effect transistor.
4. DC input resistance-RGS
The presence of effects tube input (i.e. grid source) the voltage of the UGS and flows through the gate current ratio, known as the DC input resistance. Insulated gate field effect transistor DC transmission and human resistance than pn junction FET big two orders of magnitude or more. Junction field effect transistor DC transmission and human resistance is 1 x 108 Ω, and insulated gate field effect transistor DC transmission and human resistance is 1 x 1012 Ω or more.
5. drain-source Breakdown voltage BVDS
In increasing the drain-source voltage of the process, so that the ID value for started soaring UDS, known as the drain-source Breakdown voltage. BVDS determines the FET's use of voltage.
6. BVGS gate-source Breakdown voltage
On-field effect tube, reverse saturation current starts to soar at UGS value, which is the gate-source Breakdown voltage. For insulated gate field effect tube, it is the SiO2 insulating layer Breakdown voltage.