| 摘要 |
A circuit (100) that senses a process variable (PROC. VAR.), comprises a voltage divider (106) that includes first (102) and second (104) capacitances. At least one of the capacitances is varied by the process variable. Divider ends (128,130) receive modulated potentials (El, E2), and a divider center tap (108) coupled to a detector. The detector has a detector output (118) representing carrier frequency range components. A control circuit (120) controls a baseband envelope of the modulated potentials as a function of the detector output. |
