Click here for production status of specific part numbers. Evaluates: MAX40027 MAX40027 Evaluation Kit General Description Quick Start The MAX40027 evaluation kit (EV kit) is a fully assembled Required Equipment electrical demonstration kit that provides a proven design MAX40027 EV kit to evaluate the MAX40027 ultra-low 280ps propagation 6 matched-length SMA cables (preferably up to delay, ultra-low dispersion dual comparator. The board 18GHz capable), 2 feet, or less, in length provides layout options that allow the input termination to +3.6V, 100mA DC power supply be easily modified for alternative input terminations. The High-speed signal generator with differential outputs comparator outputs are designed to drive low voltage capable of generating square waves with < 500ps differential signal outputs (LVDS). The LVDS outputs help rise times. (e.g., HP 8131A) minimize power dissipation and interfaces directly with High-speed oscilloscope with 50 termination high speed interconnect devices, FPGAs and CPUs. The MAX40027 comparator is ideal for time of flight distance Procedure measurement applications. The MAX40027 EV kit is fully assembled and tested. This evaluation kit demonstrates the MAX40027. Follow the steps below to verify board operation. Caution: Do not turn on power supply until all connections Features are completed. Fast Propagation Delay: 280ps (Typ) 1) Set the power supply to +3.3V. Disable the power Low Over-Drive Dispersion: 25ps supply. (V = 10mV to 1V) OV 2) Connect the negative terminal of the power supply Supply Voltage 2.7V to 3.6V to the GND pad. Connect the positive terminal of the power supply to the V1 SUPPLY pad. 45.9mW at 2.7V Supply (Per Comparator) 3) Set the signal generator to produce an output Power-Efficient LVDS Outputs square-wave signal of 100mV differential at a P-P -40C to +125C Temperature Range frequency of 250MHz with a common mode voltage Ordering Information appears at end of data sheet. of +2.5V. Disable the signal generator outputs. MAX40027 EV Kit Photo 319-100508 Rev 0 2/20MAX40027 Evaluation Kit Evaluates: MAX40027 4) Connect the signal generator differential outputs to Input and Output Termination the edge-mount SMA connector marked IN1+ INPUT Input Termination and IN1- INPUT. Terminating Inputs with a 50 Oscilloscope 5) Enable power supply. Enable the signal generator. By default, the EV kit is designed to terminate the inputs 6) Verify that the supply current is within 5% of 35mA when 50 oscilloscope probes are connected to the INx+ 7) Monitor and verify inputs IN1+ 50 and IN1- 50 50 and INx- 50 termination SMA edge connectors. with the oscilloscope. The oscilloscope must be When inputs from a signal generator are connected to the configured for 50 input termination. INx+ INPUT and INx- INPUT SMA connector inputs, INx+ 8) Monitor and verify outputs OUT1+ and OUT1- with 50 and INx- 50 are used to terminate the input signals the oscilloscope. The oscilloscope must be configured with a 50 oscilloscope. This enables the input signals for 50 input termination. to be observed at the oscilloscope and at the same time terminates the micro-strip line. Populate R5, R2, R6, and 9) To test comparator 2, repeat steps 4 to 8 but using R3 (or R7, R10, R9, and R11 for comparator 2) resistors the inputs and outputs intended for comparator 2. with 0 resistors when operating this way. Detailed Description of Hardware When a 50 Oscilloscope is Not The MAX40027 EV kit provides a proven design to evaluate Terminated at Inputs MAX40027 dual comparator. The device offers ultra-low When inputs from a signal generator are connected to the 280ps propagation delay, ultra-low dispersion of 25ps. INx+ INPUT and INx- INPUT SMA connectors and when it is not desired to terminate the inputs to a scope, then the Supply Voltage 0 resistor at R2 and R3 (or R10 and R11 for comparator The MAX40027 EV kit operates from standard supply 2) resistors must be de-populated and the 100 termination levels +2.7V to +3.6V. Connect the positive and negative resistor must be populated at R1/R8. supply voltages (ground return) to V1 SUPPLY and GND This is helpful when high-speed devices (TIAs, differential pads, respectively. amplifiers) connect directly to the inputs of MAX40027 for Inputs signal discrimination. The MAX40027 EV kit provides an efficient and simple Output Termination method to evaluate the comparator. The inputs to the device are from INx+ INPUT and INx- INPUT SMA Terminating Outputs with a 50 Oscilloscope connectors. INx+ 50 and INx- 50 SMA connectors By default, the EV kit is designed to terminate the outputs serve as terminating leads at the input when using an when a 50 oscilloscope is connected to the OUTx+ and oscilloscope to terminate and observe the input signal. OUTx- SMAs. C3 and C4 (or C7 and C8 for comparator During this condition R1 is not populated. When not using 2) AC coupling capacitors couple the outputs to the 50 INx+ 50 and INx- 50 connectors, R1/R8 should be oscilloscope inputs. R4/R12 termination resistor is not populated with 100. The differential inputs accept input populated in this case. signals in the common mode range from +1.5V to V + 0.1V. CC When a 50 Oscilloscope is Not Outputs Terminated at Inputs When connecting to a subsequent high-speed device OUTx+ and OUTx- SMA connectors access the MAX40027 outputs. Both OUTx+ and OUTx- output traces are in designed to accept LVDS inputs, then C3 and C4 (or C7 and C8 for comparator 2) capacitors must be replaced default AC- coupled for easy evaluation when connecting to a 50 terminated oscilloscope. The outputs OUTx+ with 0 resistor shorts and R4/R12 resistor must be populated with 100 termination. and OUTx- are 50 single-ended characteristic lines either terminated by an oscilloscope or a subsequent high-speed device. The outputs are LVDS levels. When terminating with a scope, the outputs are AC coupled. When connecting the outputs to an LVDS device such as an FPGA, replace the AC coupling capacitors C3 and C4 (or C7 and C8 for comparator B) with 0 shorts and R4/ R12 populated with 100 termination resistor. Maxim Integrated 2 www.maximintegrated.com