TDC Module Design For TOF Chip Using SMIC 0.13μm Customized Process Standard Cell Library

The TOF(Time-of-Flight)chip is a sensor used to precisely measure the depth information of a scene.It’s widely used in military,aerospace,navigation,communications,and other areas of the laser ranging of national defense construction.The single photon flight time quantization is the important technology of TOF chip,which is used in recording the depth information by measuring a single photon emission to the objects in TOF chip.TCSPC(Time-correlated singlephoton counting)is applied in the design of TOF chip,which quantize the clock count of the flight time.The precision of the TCSPC is important of the TOF chips’ qualities.TDC(Time-to-Digital Converter)is the core in the TCSPC module.This paper introduced the high precision design of the TDC circuits,which includes TDC control module,TDC measurement module,and TDC decoding module.The TDC control module is used to control the start and stop of TDC measurement module.TDC measurement module is designed with three-level structure,the time cycle counting method and two Vernier-TDCs.TDC decoding module is built up on the standard cell library based on the PDK of SMIC 0.13μm.The process of the semi-custom IC design is coding the TDC decoding module with Verilog,testing the code with Modelsim,transforming the library built up based on SMIC 0.13μm to Synopsys form,using the Synopsys’ library for building the circuit of the TDC decoding module,and verifying the circuit on the Virtuoso.In this paper,the design results include:1)The circuit of TDC control and measurement module was built to get a higher precision on the three level circuit of the measurement module2)The standard cell library,which has completed 8 kinds of basic logic unit with different drive abilities,was built for the synthesis’ tools and timing optimization in automatic place & route.3)The Synopsys tool was used for the synthesis and layout;the correctness of cell library was validated;the layout of TDC decoding module was generated,and the validation work was completed to prove that the standard cell library.