Hello,
I am planning to use below circuit as voltage clamping for voltages > 12V up to 28V.
And it does as expected (at least in simulation) however I am not understanding its working properly:
Here are my doubts:
1. As per below configuration, Vg = 14V
Vgs (M1/M2)= ~2.1V,
VTH (M1/M2) = 1.65V (from the datasheet of RSQ015N06, attached Vth vs temp graph below)
VDS(M1) = 16V
VDS(M2) = 67mV
For Cutoff:
Vgs<Vth (which is not the case, so both M1 & M2 are not in cutoff)
For Linear:
Vgs > Vth [true for both M1 and M2]
Vds < Vgs  Vth [False for M1 , true for M2?? (I am referring simulation results)]
For Saturation:
Vgs > Vth [true for both M1 and M2]
Vds > Vgs  Vth [True for M1 & False for M2]
From above conditions;
M2 is in linear mode and M1 is in saturation?? This doesn't look right, I am not sure what I am missing.
However as per functionality, M1 should be ON, M2 should be OFF and body diode of M2 is ON in order to complete the circuit.
And M1 should be in Linear mode for dropping the voltage?
I will appreciate your responses.
I am planning to use below circuit as voltage clamping for voltages > 12V up to 28V.
And it does as expected (at least in simulation) however I am not understanding its working properly:
Here are my doubts:
1. As per below configuration, Vg = 14V
Vgs (M1/M2)= ~2.1V,
VTH (M1/M2) = 1.65V (from the datasheet of RSQ015N06, attached Vth vs temp graph below)
VDS(M1) = 16V
VDS(M2) = 67mV
For Cutoff:
Vgs<Vth (which is not the case, so both M1 & M2 are not in cutoff)
For Linear:
Vgs > Vth [true for both M1 and M2]
Vds < Vgs  Vth [False for M1 , true for M2?? (I am referring simulation results)]
For Saturation:
Vgs > Vth [true for both M1 and M2]
Vds > Vgs  Vth [True for M1 & False for M2]
From above conditions;
M2 is in linear mode and M1 is in saturation?? This doesn't look right, I am not sure what I am missing.
However as per functionality, M1 should be ON, M2 should be OFF and body diode of M2 is ON in order to complete the circuit.
And M1 should be in Linear mode for dropping the voltage?
I will appreciate your responses.
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