LTC2385-18 PIN FUNCTIONS VDDL (Pins 30, 31): 2.5V Analog Power Supply. The close to the pin. If VCM is not used, the bypass capacitor range of VDDL is 2.375V to 2.625V. The two pins should is not necessary as long as the parasitic capacitance on be shorted together and bypassed to GND with 0.1μF and the VCM pin is under 10pF. 10μF ceramic capacitors. Exposed Pad (Pin 33): The exposed pad on the bottom VCM (Pin 32): Common Mode Output. VCM, nominally of the package. Connect to the ground plane of the PCB 2.048V, can be used to set the common mode of the ana- using multiple vias. log inputs. Bypass to GND with a 0.1μF ceramic capacitor FUNCTIONAL BLOCK DIAGRAM VDD VDDL OVDD CNV TWOLANES CONTROL LOGIC TESTPAT PD CLK IN+ + DCO SERIAL 18-BIT, 5Msps ADC LVDS DA IN– INTERFACE – DB VCM 0.5 15k 2 2.048V REFERENCE GND REFGND REFBUF REFIN 238518 BD 238518f 10 For more information www.linear.com/LTC2385-18 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Converter Characteristics Dynamic Accuracy Internal Reference Characteristics Reference Buffer Characteristics Digital Inputs and Digital Outputs Power Requirements ADC Timing Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Timing Diagram Applications Information Package Description Typical Application Related Parts