×

DA converter circuit provided with DA converter of segment switched capacitor type

  • US 7,095,350 B2
  • Filed: 06/22/2005
  • Issued: 08/22/2006
  • Est. Priority Date: 06/23/2004
  • Status: Expired due to Fees
First Claim
Patent Images

1. A DA converter circuit including a DA converter of segment switched capacitor type, said DA converter comprising:

  • (a) an operational amplifier having a feedback capacity;

    (b) a plurality of M=2L capacitors which are connected in parallel to each other so as to supply electric charges to the operational amplifier;

    (c) an electrically charging switch for switching over between performing and not performing of electrically charging electric charges onto the respective capacitors; and

    (d) an electrically discharging switch for switching over between performing and not performing of electrically discharging electric charges from the respective capacitors, andwherein the DA converter circuit further comprises;

    a switch device for performing either electrically charging, the electrically discharging, grounding, or polarity inversion onto the respective capacitors; and

    a controller for controlling the electrically charging switch, the electrically discharging switch and the switch device so as to execute a process of second-order DWA algorithm for performing a second-order noise shaping of a non-linearity of the DA converter circuit for a low-pass ⊖

    Σ

    AD modulator, using the following operations;

    (A) a “

    +2”

    operation for performing the electrically charging and the electrically discharging twice onto the respective capacitors for a predetermined time interval to generate an output voltage which is a voltage of +2 times a predetermined reference output voltage;

    (B) a “

    +1”

    operation for performing the electrically charging and the electrically discharging once onto the respective capacitors for the time interval to generate an output voltage which is a voltage of +1 times the reference output voltage;

    (C) a “

    0”

    operation for not performing any electrically charging and electrically discharging onto the respective capacitors for the time interval to generate an output voltage which is a voltage of a grounding electric potential; and

    (D) a “



    1”

    operation for performing the electrically charging once onto the respective capacitors and thereafter inverting polarities of the respective capacitors for the time interval to generate an output voltage which is a voltage of −

    1 times the reference output voltage.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×