Dec 16, 2007 #1 0 020170 Full Member level 4 Joined Jan 31, 2005 Messages 231 Helped 3 Reputation 6 Reaction score 1 Trophy points 1,298 Activity points 2,221 Some circuit needs resistor to adjust voltage vallue. Especially, resistor used in Voltage divider circuit. In cmos process, process variation of resistor is too large to ignore. in additional to Aread of Resistor is big compare to NMOS or PMOS Nevertheless, Why We use Resistor in Voltage divider circuit instead of MOS? May we use diode-connected MOS in the voltage divider circuit instead of resistors?
Some circuit needs resistor to adjust voltage vallue. Especially, resistor used in Voltage divider circuit. In cmos process, process variation of resistor is too large to ignore. in additional to Aread of Resistor is big compare to NMOS or PMOS Nevertheless, Why We use Resistor in Voltage divider circuit instead of MOS? May we use diode-connected MOS in the voltage divider circuit instead of resistors?
Dec 16, 2007 #2 R renwl Advanced Member level 1 Joined Apr 26, 2004 Messages 452 Helped 27 Reputation 54 Reaction score 5 Trophy points 1,298 Location shanghai,china Activity points 1,805 I think the second order effect of the mos make the accuracy of the voltage very low. however, the resistor used in Voltage divider circuit has better relative accuracy.
I think the second order effect of the mos make the accuracy of the voltage very low. however, the resistor used in Voltage divider circuit has better relative accuracy.
Dec 16, 2007 #3 Z zyyang Member level 3 Joined Jan 19, 2006 Messages 54 Helped 3 Reputation 6 Reaction score 1 Trophy points 1,288 Location P.R. CHINA Activity points 1,560 in fact , the mismatch in mos transistors is the same with the resisters.
Dec 16, 2007 #4 M milkdragon Member level 3 Joined May 3, 2007 Messages 64 Helped 12 Reputation 24 Reaction score 7 Trophy points 1,288 Activity points 1,604 I think resistor gives you more flexibility to have a more wide range of voltage from resistive voltage divider. A diode connected MOS is bounded to Vth.
I think resistor gives you more flexibility to have a more wide range of voltage from resistive voltage divider. A diode connected MOS is bounded to Vth.
Dec 17, 2007 #5 grittinjames Advanced Member level 1 Joined Jun 1, 2006 Messages 479 Helped 44 Reputation 90 Reaction score 32 Trophy points 1,308 Location bangalore india Activity points 3,985 ask this question in layout design cri
Dec 17, 2007 #6 A analog_prodigy Full Member level 2 Joined Jul 19, 2007 Messages 140 Helped 14 Reputation 28 Reaction score 2 Trophy points 1,298 Location India Activity points 1,936 As per my exp, the resistance value has to be changed to +/- x% for all other process corners other than typical corner, given by foundary
As per my exp, the resistance value has to be changed to +/- x% for all other process corners other than typical corner, given by foundary
Dec 17, 2007 #7 L lovexxnu Junior Member level 1 Joined Dec 14, 2007 Messages 18 Helped 1 Reputation 2 Reaction score 1 Trophy points 1,283 Activity points 1,372 The ratio of resistors is much smaller than any single resistor, it is acceptable for IC design Added after 2 minutes: analog_prodigy said: As per my exp, the resistance value has to be changed to +/- x% for all other process corners other than typical corner, given by foundary Click to expand... but they have the same change, so it has no impact on voltage divider.
The ratio of resistors is much smaller than any single resistor, it is acceptable for IC design Added after 2 minutes: analog_prodigy said: As per my exp, the resistance value has to be changed to +/- x% for all other process corners other than typical corner, given by foundary Click to expand... but they have the same change, so it has no impact on voltage divider.