| 摘要 |
PURPOSE:To prevent the development of nonlinear error, by the constitution that the current from the output terminal of the current switch can not flow to the ground line. CONSTITUTION:When a signal of high level is fed to the digital input terminals 1-8, the transistors 21-28 constituting the current switches 71-78 to cut of the transistors 31-38, and the current from the constant current sources 111-118 in binary weight with the resistors 91-98 and 101-108 flows to the common current summing point 10 through the output terminals A51-58. When a signal of low level is fed to the digital input terminals 1-8 on the contrary, the current flowing to the output terminals 61-68 of the current switches 71-78 flows directly to the minus current supply terminal 123 from the positive power supply terminal 120 without passing through the ground line 69, thereby causing to making independent the current flowing to the ground terminal 60, of the input digital signal. |
