Demonstration circuit EVAL-LTC6563-TQFN features the LTC6563 four-channel transimpedance amplifier (TIA) with output multiplexing. This demo kit, EVAL-LTC6563TQFN-EZKIT shipped along with the SDP-K1 controller board, has 4 installed single APD’s which allows optical testing of the TIA functionality. Electrical testing using an external lab pulse generator, as the input current pulse, is also possible with small board modifications.
With its 20kΩ transimpedance gain and 90μA linear input current range, the LTC6563 is ideal for LIDAR receivers using Avalanche Photodiodes (APD). The LTC6563 operates from 3.3V single supply and consumes only 194mW (depending on output mode) for 4 channels. Utilizing the LTC6563’s output MUX, multiple LTC6563 devices can be combined to a single output. The LTC6563’s fast overload recovery makes it well-suited for LIDAR receivers. The LTC6563’s differential output can swing 2VP-P into a 100Ω load, ideal for driving a high-speed ADC directly.
The LTC6563 is packaged in a compact 3mm × 5mm 24-pin leadless QFN package with an exposed pad for thermal management and low inductance.
The EVAL-LTC6563-TQFN utilizes four installed 400-1100nm APD sensors feeding the LTC6563 for current-to-voltage conversion and amplification. The APDs are DC-coupled to the TIAs to facilitate fast output multiplexing and channel switching. Alternatively, with small board modifications, it is possible to electrically excite the LTC6563 using a lab generator tied to SMA connectors provided on the board and voltage-to-current resistors on the board. The EVAL-LTC6563-TQFN is intended to demonstrate time-domain measurements into 50Ω systems.
