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Attached is the full view of the two rails.
I need solutions for the current sources. It didn´t work with just MOSFETs. Current sources have to controlable through 0V/5V input.
I tried it at first with a ideal current source. With increased current, the output voltage decreases, because it is pulled from the 150V supply rail. So, i really need low current of maximum 100uA which is difficult to find.
Hi,
i need a constant negative current source that generates 100mA/0mA. The circuit worked with ideal current sources.
Then i tried to use a MOSFET on the source side connected to ground, gate signal is 5V/0V - but this doesn´t work...i guess because the current is higher and unstable. Max. Vds...
Hi,
i have a problem with the op amp in the ahdlLib in Cadence.
I connected it as voltage follower with sinusoidal Vin+ (Amplitude 2.5V, f=10k), Vdd=5V.
I set the following parameters for the opamp:
gain=10000
frequ_unitygain=100M
rin=10M
vin_offset=0
ibias=0 (input current)...
Ok, so it is how i thought with source connected to the resistor divider.
But still, isn´t it a Problem that when the NMOS is off, the gate voltage is uncertain.
Don´t you think it is better to add something to the gate node that fixes the gate node to a certain voltage Level, when the NMOS is...
Did i understand this correct? (See Picture)
Some more questions to it:
- Isn´t it better to connect the source to the Input instead of the drain? Then the Vgs is also Independent of the Output.(See Picture)
- Another important question is, isn´t it a Problem that Vg is on a unknown...
Yes, i can use external PMOS PHC2300P.
Two Mosfets because i throught of resistive divider with same resistor Rds,on to make the source Connection Zero potential.
If i use just one Mosfet, it is impossible to implement, because i always have Problems with Vgs. Then i have 200V on the source...
The MOSFET itself has a Maximum Vgs of 20V, but i only have 5V supply voltage.
I try to Switch 200V (generated from a boost converter) to a load by a control signal(0/5V).
But i always have the problem that a source voltage of 200V forces me to have a gate voltage of at least 205V.
Therefore, i...
Hi,
i like to add a virtual ground between two Switches.
The idea is, i connect two NMOS in series connected on the source sides.
Then i want to add a virtual ground between the Switches. (see pic)
Why i need this? Because of my limitations.
Vgs,max=5V, Vds,max=300V, Vgate,max=5V, Vin=200V ...
I can not choose any OpAmp. It is a integrated circuit and i only have 1 OpAmp in my technology available.
That is the reason why the OpAmp idea is out.
I am now looking for a solution without OpAmp.
the problem is, i can not reduce the 5MOhm total output resistance (3 resistors in series), because it is the equivalent load.
The -60V are generated by a charge pump, that is supplied by a 5V battery.
ripply should be max. 10%
equivalent load is 5MOhm resistor and 10nF capacitor.
Body Diode Problem in Load Switch?
I have two rails (-60V/+200V) and i want to connect those rails to the load through integrated PMOS switches.
I have limited Vgs to around -2V through zener diodes. leakage currents are flowing through a resistor.
What the circuit does is: the output...
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