Ramp generator and image sensing device including the same

An image sensing device comprising:

• a pixel array configured to output a pixel signal by converting incident light into an electrical signal;
• a ramp generator configured to adjust a value of a reference current applied to a first node based on a plurality of control signals, configured to adjust a value of a current applied to a second node based on control signals of some upper bits from among the plurality of control signals, and configured to generate a ramp signal based on a mirrored current according to the first node and the second node;
• an analog-to-digital converter (ADC) configured to output analog-to-digital conversion data based on the pixel signal and the ramp signal;
• and
• a timing controller configured to generate the plurality of control signals.