Analog Devices LTC6563 Four-Channel Cross-Resistance Amplifier (TIA) with Output multiplexing

     ADI's LTC6563 is a low-noise four channel TIA with a bandwidth of 600 MHz. 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 has an optional 22.2 k Ω/16.7 k Ω/11.1 k Ω/5.55 k Ω transimpedance gain (RT) and 90 μ A Linear input current range. With 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 consumes between 194 mW and 325 mW on a 3.3 V power supply, depending on the output mode. The internal 4-to-1 MUX simplifies the system design. In addition, the external multiplexing function allows channels to be expanded to 64 channels to save space and power. 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 can swing up to 2 VP-P and drive 100 Ω external differential load at the same time.

     The demonstration circuit EVAL-LTC6563-TQFN adopts LTC6563 four channel TIA with output multiplexing function. The demo kit EVAL-LTC6563TQFN-EZKIT is shipped with the SDP-K1 controller board, which has four single APDs installed, allowing optical testing of TIA functions. The electrical test using the external laboratory pulse generator as the input current pulse can also be realized by making small changes to the circuit board