SNOAA83 December   2021 TLV3601 , TLV3601-Q1 , TLV3603 , TLV3603-Q1

 

  1.   1
  2.   Design Steps
  3.   Simulation Results
  4.   Design References
  5.   Design Featured Comparator
  6.   Design Alternate Comparator

Design Goals

System Supply Photodiode Input
Current Pulse Width		 Transimpedance Amplifier Output Type Maximum Propagation Delay
5 V

3 ns

 High Bandwidth 100-mV output swing Single-ended 4 ns

Design Description

LiDAR Receiver Circuit

This circuit must be able to detect a 3-ns pulse received on a photodiode from a light pulse. To do this, a transimpedance amplifier and a high-speed comparator are required. To meet the propagation delay requirement, this design uses the OPA858 5.5-GHz gain bandwidth product, decompensated transimpedance amplifier with FET inputs and the TLV3601 2.5-ns high-speed rail-to-rail comparator with push-pull outputs.

Design Notes

  1. Select a high-speed comparator that has narrow pulse width detection capability better than 3 ns
  2. Derive the reference for the transimpedance amplifier and comparator from the same voltage source
  3. Verify stability of the transimpedance amplifier configuration with selected photodiode