EVAL-LTC2065/LTC2068-TQFN User Guide UG-1761 One Technology Way P.O. Box 9106 Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 Fax: 781.461.3113 www.analog.com Evaluating the LTC2065 and LTC2068 A Supply Current, Low I , Zero-Drift, Op Amp B application circuits and configurations, such as active loop filters, FEATURES transimpedance amplifiers (TIAs), and sense amplifiers. Fully featured evaluation board for the LTC2065/LTC2068 Figure 1 shows the top view of the evaluation board, and Figure 2 Enables efficient prototyping User defined circuit configuration shows the bottom view. Simplified connection to test equipment and other circuits EVALUATION BOARD PHOTOGRAPHS EVALUATION KIT CONTENTS EVAL-LTC2065/LTC2068-TQFN EQUIPMENT NEEDED Dual-output dc power supply Dual-channel signal generator Oscilloscope Banana jack to grabber cables BNC to grabber cables DOCUMENTS NEEDED LTC2065/LTC2068 data sheet GENERAL DESCRIPTION The EVAL-LTC2065/LTC2068-TQFN evaluates the LTC2065 and LTC2068 16-lead, quad-channel, lead frame chip scale package (LFCSP)/quad flat no-lead (QFN) operational amplifier (op amp). The EVAL-LTC2065/LTC2068-TQFN is a prepopulated Figure 1. EVAL-LTC2065/LTC2068-TQFN, Primary Side board using a gain of 2 configuration with a low-pass filter at the noninverting input. This filter has a cutoff frequency of 480 Hz for the LTC2065 and 2.4 kHz for the LTC2068. This frequency minimizes the effect of chopper clock feedthrough to at least a decade below the internal chopping frequency of 5 kHz and 25 kHz for the LTC2065 and LTC2068, respectively. Signal bandwidths are also limited due to slew rate limitations of the devices. The EVAL-LTC2065/LTC2068-TQFN design allows simplified and efficient use. Bulk test points are used for the inputs and outputs. The optimized EVAL-LTC2065/LTC2068-TQFN ground plane, component placement, and power supply allow maximum circuit flexibility and performance. The exposed pad (EPAD) is shorted to the V pin (also connected to the VS turret), which is required for device operation. The EVAL- LTC2065/LTC2068-TQFN combines surface-mount technology (SMT) with almost all components being 0805 in size to provide simplified installation and the option to replace and solder when Figure 2. EVAL-LTC2065/LTC2068-TQFN, Secondary Side needed, except for the bypass capacitors (C1 to C4) that are Refer to the LTC2065 and LTC2068 data sheet for full fixed in 0603 sizes. The EVAL-LTC2065/LTC2068-TQFN also specifications in conjunction with this user guide when using has unpopulated resistor and capacitor pads, which provide the the EVAL-LTC2065/LTC2068-TQFN. user with the options and flexibility to implement different PLEASE SEE THE LAST PAGE FOR AN IMPORTANT WARNING AND LEGAL TERMS AND CONDITIONS. Rev. A Page 1 of 7 23178-002 23178-001UG-1761 EVAL-LTC2065/LTC2068-TQFN User Guide TABLE OF CONTENTS Features .............................................................................................. 1 Power Supply Consideration .......................................................3 Evaluation Kit Contents .................................................................. 1 Initial Board Configuration .........................................................3 Equipment Needed ........................................................................... 1 Using the Evaluation Board for Testing ....................................3 Documents Needed .......................................................................... 1 Evaluation Board Schematics and Artwork ...................................4 General Description ......................................................................... 1 Ordering Information.......................................................................7 Evaluation Board Photographs ....................................................... 1 Bill of Materials .............................................................................7 Revision History ............................................................................... 2 Evaluation Board Quick Start Procedures .................................... 3 REVISION HISTORY 7/2020Rev. 0 to Rev. A 3/2020Revision 0: Initial Version Changed Evaluation Board Name from EVAL-LTC2065-TQFN to EVAL-LTC2065/LTC2068-TQFN ......................... Throughout Changes to User Guide Title, Features Section, Documents Needed Section, General Description Section, and Figure 1 ..... 1 Changes to Table 1 ........................................................................... 7 Rev. A Page 2 of 7