In order to suit the lidar ranging system，a wide-range time-to-amplitude converter（TAC）with adjustable range and resolution is designed. The TAC ASIC employs a counter in combination with an analog voltage ramp，which significantly expands the range. The circuit is designed in a 180 nm CMOS technology，with a single TAC channel area of 400 μm×260 μm. The conversion period and sampling period of the overall circuit are controlled by external signals，and the range and resolution can be adjusted to suit applications in complex environments. Simulation results show that the TAC has a range of 6.4 μs at 20 MHz operating clock，a measurement resolution of 50 ps，a differential nonlinearity of ±0.05 LSB，and an integral nonlinearity of ±0.8 LSB. The TAC has good performance and is suitable for wide-range lidar ranging system.