| 摘要 |
PURPOSE:To prevent the deterioration of the relative accuracy due to the poten tial gradient for the output of a constant current source, by adding the MOS transistors (Trs) which perform the source-follower actions to plural constant current source circuits requiring the relative accuracy. CONSTITUTION:The MOS Trs Q2/Q5 and Q3/Q6 supply steadily and continuously currents I01 and I02. It is supposed that these Trs Q2/Q3 and Q5/Q6 have the satisfactory relative accuracy. A drain current IDS which gives the saturated actions to those MOS Tr is shown in an equation. Both beta and VT can be set approximately equal to each other between the Trs Q2/Q3 and Q5/Q6. The outputs I01 and I02 of both constant current source can be set equal to each other when the same gate-source voltage VGS is secured between the Trs Q2/Q3 and Q5/Q6. No steady current flows to two bias lines VB1 and VB2 since these lines have inputs to a gate. Therefore the potential ramp is never caused by bias line impedances r4-r9.
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