Patent ID: 6407626
Filing Date: 2002-06-18
Classification: H03K

Abstract:
A symmetrical filter, comprising:an input voltage node (Vin) for receiving an input signal; an intermediate node; a comparator coupled to a supply voltage node (Vsup), a ground voltage node (Vgnd), a capacitor voltage node (Vcap), and a reference voltage node (Vref); a voltage divider coupled between Vsup and the Vgnd and also connected to the Vref; a capacitor coupled between the Vgnd and the Vcap; a current regulator coupled to the Vsup, the Vgnd, and the Vcap; an invertor block coupled between the Vin and the intermediate node; a pull-up switch coupled between the Vsup and the Vcap; a pull down switch coupled between the Vgnd and the Vcap; a control logic coupled to the pull up switch, the pull down switch and the Vin; and an output node (Vout) coupled to the comparator for providing an output signal.