ADI's LTC6563 is a low noise quad TIA with 600 MHz bandwidth. The low noise, wide linear range and low power consumption of the LTC6563 TIA are ideal for LIDAR receivers using avalanche photodiodes (APDs) and photodiodes (PDs). The amplifier features selectable 22.2 kΩ/16.7 kΩ/11.1 kΩ/5.55 kΩ transimpedance gain (RT) and 90 μA linear input current range. Using an APD with a total input capacitance of 0.5 pF, the input current noise density is 1.8 pA/√Hz at 100 MHz and 3.7 pA/√Hz at 600 MHz. The LTC6563 dissipates between 194 mW and 325 mW on a 3.3 V supply, depending on the output mode. Internal 4-to-1 MUX simplifies system design.

      Additionally, an external multiplexing function allows channel expansion up to 64 channels for space and power savings. Fast overload recovery and fast channel switching make the LTC6563 ideal for LIDAR receivers with multiple APDs. The built-in high-speed differential ADC driver swings up to 2 VP-P while driving an external differential load of 100 Ω.

      Demonstration circuit EVAL-LTC6563-TQFN features the LTC6563 quad TIA with output multiplexing. The demo kit, EVAL-LTC6563TQFN-EZKIT, ships with the SDP-K1 controller board, which has four single APDs installed, allowing optical testing of TIA functions. Electrical testing using an external lab pulse generator as the input current pulse can also be accomplished with small changes to the circuit board.