MOSFET Characteristics

Drain Current Characteristics of a 2N7000 MOSFET

Brief Summary
PV2 is connected to the GATE. PV1 is connected to source via a 1K resistor. And DS current is measured as a function of the voltage .
February 09, 2020
Jithin B.P.

Introduction

To study n type eMOSFET characteristics.

TODO: Add more details to blog.

Procedure

  • Connect PV2 to GATE.
  • Connect PV1 to DRAIN via a 1K resistor
  • Source is grounded.
  • Connect A1 to the DRAIN. This is the Drain voltage. This enables measuring current as well ( I_DS = (PV1 - A1)/1K )

Mosfet photo for drain characteristics

Results

Mosfet drain characteristics

The drain current is plotted against the drain-source voltage for various values of GATE voltage ranging from 1.65 volts to 2.0 Volts.

Below 1.65V gate input, the MOSFET does not conduct enough to obtain characteristics

Code

import eyes17.eyes    
p = eyes17.eyes.open()
from pylab import *
import time
#set the inital value of vss
xlabel('Drain Voltage Vds (Volt)')
ylabel('Drain Current Id (Amp)')

pv2 = 1.65
ion() #Enable interactive plotting
while pv2 <= 2.0:
	vdsa = []
	idra = []
	p.set_pv2(pv2)
	p.set_pv1(0)
	time.sleep(0.2)
	#set the intial value of vdd
	pv1 = 0.0
	while pv1 <= 4.8:
		p.set_pv1(pv1)
		#Measure voltage vd to find current id and voltage vds
		a1= p.get_voltage('A1')
		#Find current id for rd=1000 Ohm
		idr = (pv1-a1)/1000.
		#find vds
		vds = a1
		#append id & vds in the arrays
		idra.append(idr)
		vdsa.append(vds)
		print(a1,vds, idr)
		pv1 += 0.1
	plot(vdsa,idra)
	pause(0.5)
	pv2+=0.05	
show()

SEE also