Title:
FILTER CIRCUIT
Document Type and Number:
Japanese Patent JPH01137811
Kind Code:
A
Abstract:
PURPOSE:To easily eliminate the noise due to sampling of a switched capacitor filter by using an analog filter. CONSTITUTION:MOSFET analog filters 2, 4 are active filters including capacitors 23, 24, resistors and an operational amplifier 22, and the resistors are made of drain-source resistors of MOSFETs 21-1, 21-2 and gate-source voltage setting circuits 26-1, 26-2 and capacitors 25-1, 25-2 are provided as a means supplying a bias voltage setting the drain-source resistance between the gate and source on the MOSFETs 21-1, 21-2. Thus, the reflection of a high frequency noise onto a basic band is reduced to decrease the circuit scale.
Inventors:
SAWAHASHI MAMORU
MUROTA KAZUAKI
MUROTA KAZUAKI
Application Number:
JP29878087A
Publication Date:
May 30, 1989
Filing Date:
November 25, 1987
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE
International Classes:
H03H19/00; (IPC1-7): H03H19/00
Attorney, Agent or Firm:
Naotaka Ide