Control systems having an analog control unit that generates an analog value responsive to a digital value and having twice the resolution of the least significant bit of the digital value and methods of operating the same

A method of operating a control system, comprising:

• generating a digital value responsive to a difference between an output analog value and a reference value;
• generating a control signal;
• generating a first analog value responsive to the digital value;
• generating a second analog value responsive to the control signal at a resolution that is twice that of a resolution associated with a least significant bit of the digital value;
• and
• generating the output analog value by combining the first and second analog values.

A control system for performing analog control, comprising:

• a counting unit, which counts a number of clock signals that are input while an evaluation signal is activated in response to a first control signal and, upon deactivation of the evaluation signal, outputs the counted number of clock signals as a first count value of n bits and a second count value of n bits;
• a digital control unit, which compares the first count value and the second count value, performs a predetermined operation based on the comparison result, and outputs the operation result as a third count value of n bits;
• and
• an analog control unit, which controls an analog value in response to the third count value and receives a second control signal of 1 bit that can control a half of a minimum analog value that varies in response to a minimum change in the third count value.

A method of controlling an analog value, comprising:

• comparing an analog value with a reference value and generating a first control signal at a first level or second level based on the comparison result;
• counting the number of pulses of clock signals while an evaluation signal is activated in response to the first control signal and outputting the counted number of clock signals as a first count value of n bits and a second count value of n bits upon deactivation of the evaluation signal;
• comparing the first count value and the second count value, performing a predetermined operation based on the comparison result, and outputting the operation result as a third count value of n bits;
• and
• controlling the analog value in response to the third count value and receiving a second control signal of 1 bit that can control a half of a minimum analog value that varies in response to a minimum change in the third count value.