This is a multi-part message in MIME format. ------=_NextPart_000_0008_01C6762A.A5671CA0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit Hello everybody, I am trying to make an instrumentation amplifier (INA) out of 3x LF356 JFET opamps. And cannot use a integrated INA as I don't have any and samples may take a few days to reach me. Please see the attached gif of an INA. To make things easy: R1=R2 and R3/R4=R5/R6. But if R1 is not exactly equal to R2, can I use a trimpot as one of R3,R4,R5 or R6 to trim away any common mode gain? Which one of these four resistors should be replaced by it? Thanks, Mohit. ------=_NextPart_000_0008_01C6762A.A5671CA0 Content-Type: image/gif; name="INA.gif" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="INA.gif" R0lGODlhxAESAfcAAAAAAAEBAQICAgMDAwQEBAUFBQYGBgcHBwgICAkJCQoKCgsLCwwMDA0NDQ4O Dg8PDxAQEBERERISEhMTExQUFBUVFRYWFhcXFxgYGBkZGRoaGhsbGxwcHB0dHR4eHh8fHyAgICEh ISIiIiMjIyQkJCUlJSYmJicnJygoKCkpKSoqKisrKywsLC0tLS4uLi8vLzAwMDExMTIyMjMzMzQ0 NDU1NTY2Njc3Nzg4ODk5OTo6Ojs7Ozw8PD09PT4+Pj8/P0BAQEFBQUJCQkNDQ0REREVFRUZGRkdH R0hISElJSUpKSktLS0xMTE1NTU5OTk9PT1BQUFFRUVJSUlNTU1RUVFVVVVZWVldXV1hYWFlZWVpa WltbW1xcXF1dXV5eXl9fX2BgYGFhYWJiYmNjY2RkZGVlZWZmZmdnZ2hoaGlpaWpqamtra2xsbG1t bW5ubm9vb3BwcHFxcXJycnNzc3R0dHV1dXZ2dnd3d3h4eHl5eXp6ent7e3x8fH19fX5+fn9/f4CA gIGBgYKCgoODg4SEhIWFhYaGhoeHh4iIiImJiYqKiouLi4yMjI2NjY6Ojo+Pj5CQkJGRkZKSkpOT k5SUlJWVlZaWlpeXl5iYmJmZmZqampubm5ycnJ2dnZ6enp+fn6CgoKGhoaKioqOjo6SkpKWlpaam pqenp6ioqKmpqaqqqqurq6ysrK2tra6urq+vr7CwsLGxsbKysrOzs7S0tLW1tba2tre3t7i4uLm5 ubq6uru7u7y8vL29vb6+vr+/v8DAwMHBwcLCwsPDw8TExMXFxcbGxsfHx8jIyMnJycrKysvLy8zM zM3Nzc7Ozs/Pz9DQ0NHR0dLS0tPT09TU1NXV1dbW1tfX19jY2NnZ2dra2tvb29zc3N3d3d7e3t/f 3+Dg4OHh4eLi4uPj4+Tk5OXl5ebm5ufn5+jo6Onp6erq6uvr6+zs7O3t7e7u7u/v7/Dw8PHx8fLy 8vPz8/T09PX19fb29vf39/j4+Pn5+fr6+vv7+/z8/P39/f7+/v///ywAAAAAxAESAQAI/wD/CRxI sKDBgwgTKlzIsKHDhxAjSpxIsaLFixgzatzIsaPHjyBDihxJsqTJkyhTqlzJsqXLlzBjypxJs6bN mzhz6tzJs6fPn0CDCh1KtKjRo0iTKl3KtKnTp1CjSp1KtarVq1izat3KtavXr2DDih1LtqzZs2jT ql3Ltq3bt3Djyp1L9ymyunjzhgXh467ev4CrgrizpW/gw4iXgtj1L1Nhv4kjS/a5eKBjw5MzB+Z3 r/M9gp75vaxM8DJkzajn8usEAgAwgsBAxPnsknRB06lzy+0BAB5BeCBi2jaIW7fxtbE7EXyFSDhj hcWPSy8LIvhAEOecN4w+vbvXVyBe///j1kPmcIFEnt9+PBZZ9fd1xpF1/x5EfO8S74Eo/w+LeJjn /ZNeQtx91Zo77qiyRSPUAYCgggziB1Ec2Ok3U4ADQsceWK0NtAsIEYrVoUAfhighQ+dUB0Zz5qk3 UIYLFajViAIBYJ2IABBk44kP8QaCbwwhI+QkQhZp5JFIJpkkaXcQ4WQEMzhJRCYxbrgVjR+exmGO JIKgJY8JPQMCFg41YqYUiJip5ppstulmmyC8IhAzu9Q5AyJ17tLNdlZi1WE3d/hgS4P/ACoomA+B 8AxNGLr4kIxTVdcICFWcJSmliEKUHaOOCtjpo31GGtyk7ZhV3T+kZioRNxSO1imMFEH/6tSp//jg wz4DueeDfF3RaiuuBX2pKkFiumoQM+5kJKti1u1jn0D74NrOjVc2+yxB+9QxbJjUrhRgR8siRes/ 1oBY0KC93liuifuYuC2x3ar0rUfhDlWPKNVZMxC+okhbB7Ba3ZvvviD0+089qL57ULG1fQpSvU3V Y8sWaAHrrsL/MNzSvCFBzFS8Yk36nrDDaswSxyJ5jFS2a4H8LmtAnuxwSSoLNU4dPhislsvbetbw SzVjLLRiM6MU9NBIE4WyQXcA4PTTTt+hbKhJV53U0sc6TdAdUmt0tEraItQOugeFjZXZBo2dENpW k4S1QVpvDS7VMtXjJUKTImQ3yVDt/423y363XdLbBcU90tck2RKBDwjxJazijF8FeeOYnbu44IMX jZDh/3T9MN0bI7KrQbaIQNhBIIjOq2Cqk246xQalPjrmIhGuI9QzeN4x6A/tgwzAFCEjwj9mwE6Q D5l0A8LqAglPvPEk+Q48Ss4XbxDyyjP/T/XQ0+6R7QMZroruKfO+kHs28t2QD1Irj/BA1viQrBnu sl8oCO+PhP7dKtnvPkHxm1/92oc/74EEfDXikkBYZJLLIAIYSopga5wWniIRKYLIkNNAxgGCZAlI FATZQtc+BDAOehAIZcAgMi6owhZO0EYQbKEKWagkDQrEhOgB4UBE2KUSdlAgKJyhDP+HqD5EIfAf nCOIO+4QAZEsEQAGKIGUpkjFKQIBagC4gZQ6AIQqTjEInxhIHcwwEFXcaFp7EsgMyDbGgcQCBF6c IhfjSMcqXhFqWqyjHp00RzqCUYxkFIgZB4LGgawRkG6EYx37uMc9AiB/CjtiEnehikJ1Q4EdWWIE InAHD0JkBk8b3qOsYzdmEEQEfmlEpSxDShCYMiWgdJooD9fKVwoElQJRZWlqyZJHDk2STSxjBDyJ SY1okpOejEg3qgCAH6TxIYaxBREKIjqBnCea01TJMpv5zJFgk5qRu+ZdpNkSXwoNfLtgJhYBMAMd ceSYncQIADR3kNOBgEpK3FXpmEb/sXuWk54bsSc+B+IOfc5yIAItJyTfdUSGFLMi8EymReYpkUvO 4KADMYMIIjDQgVgUoymhqEk+ehCNctQgJFXoLwEakYdKJKIcEWlEzAAA8gnkksMsaU1dItOS0NSm hQJATg3yU54udFsNXYhLHwLTjvT0IbtwEEKIANR/RFWiIWWpRq461apyVaXn1GpDEIGInb6UicgE yVMflRA9Eeglaz1cW7t5G7gedVhJzSRa4xmSuErFr2YxJ8byasy9YtUjgIVKYski2EiKVa+b5CtJ FusUyoqlsQx9bGEje9i+avYolg0LZpH6WYs0tYGgtKVVQguW0eK1tBM5LUkAFQEA/5hBtauFbVZc qyrCMtWwJ9kFTU3XWaoAYBRu4W2mfMsQ2dJMBAAgQiW5wtqvKNeIul2Ic1GSTgCIABHFjUp1vXJd MDH3INtdCW0jYAa6TmW8XSkvj86rRODSxB2ZgK50c5vcu/Y2u/XlrE66+93wJgW+1PVvbobIpDji FiHpxUjTcNfRszrNDAYGLYBXq+DUgCBKegSABumUpxIbOMIauaSDEiQCImQYpWaIrHsru+GqyDcz WEOwQFAcUwVGNZsOUQURvJuJFx+4xsbtMGpy/FkeOxWTSYQwIqBbBST7RMdaufFkmBwRJyPWx2ZN SDdizMkZG9fKf1WyZrjsEC9/RP9rtA1kQmhqWyM/Bcu7VTOO6WlZN6s1ugCogplvM+QZVPgqeMaK liXD5oT4ua85GvJ0G8IMmpZ5t2gWr563zOeZPVokWnPHJm2pSYUsEbpmyHROEo3oTTO60+i1b0zi xgx2erAbl9xOoQ99Z1Xf2dWRafSOZS0Tw5UVyEh8SKWFKtle9xc/jf50SboLAPAKhJlVeOVSUcpE 2z64KazmMLRhLW2abNtDw222eH1dWWAnJsfjE7BRzp0JUE5J0ewGt7sRk2Nm21knLqWtt7Ocb6Ys Otj0TCtSyBpmq6b73wYv+FIO/m56Qlwo+Y3upAn+bO/QFykEtjamO96djydlve3/xTfJp2NypeBX vxv/q8SVQnF+z5woIb94UMJt430fpuVNeWKdZb5y6QBdKWOW8ZmLfpyjI8UFRNb5UHie5HGfBQCK GHlbav7zm+/c68UG+7x9Hhina1jrbOF62cV+ZbbD1e1TJztgzD5vuP+TIereitrnbneA930llPU3 eeX+F7oXheptd+gdNpp3cXv87zhBfE8Cz5j8KlzRhNeL4YkieZ5Q3jKMlzrnM5+XzQul1pZAe0Ke avnG/9rqZJlww5eu1E+1XvQ/2XvhzcC13vv+98APvvCHT/ziG//4xcci7r/u0JndPs34eZP0p0/9 6lv/+tifPiJeCIBvKxbW0Am9/2JJb8Cb1CGUKq/9dsSv7/I/BV/OTL9CWPv8iZPf/TYxvbnB/yj2 I0X3+IcT+jcTnycR9Td2AdgUAxh2zVcRBxh3CfgxkBdSvJd82fWAQAGAEcgpWdFIQ6ZBQ7ZOloWB k3d/GwggE2gTVEeCAGeCJ/gzgYVmLHgTGviCKHh1qjaD5uaCNugtKVgTnQd6l0eDPNiDJ3EzroSD h+N/QFiERqg/PgACt4UWQUgcTFhsTviEHiExIEBcalGFB6GDgJeFWsgR47AFcBRzMZgSYogSNViG 9AEf2nMRAlNgVOh2bVgSb1iG/3AgCbIgHoEMtpJyZQGGDJGHoEaGL4gl5uIRZ/+Yhoz1d4j4Zop4 gjSCRDyDEXUoctY1gZMYU5W4gYxYRBiBDBcmWmIle1hUVRHxiRmxh2X4J4FCNh9hC7ZyB4OmepTG OVyzEa44UaEYgZeySh/RDpMiAkUWiRKRRKwYK1dIiXyoEaeSKh1hDWhYZUrYUufmi88IiiIhMo24 PdWxBdPzS9bxKw7RPQdhi+yTi524jJjUjBjxiw8Bi+tYMAVRD5HTNrTiLGxDEbbQGhi2FvCFRblD EvS4ELUWDiRRGAUxDqSIVOoSjv9QjtBCSAcxDpNiaF+oWeIjj9w4hBYxYfwTEuWiLwNxMUMjMCCA kv/AL/dgi2g4TmgojgKxN9f/gi0B2Y7ZCBGcw0DPFQFAAAfIR3xQU0FEpCQueRA+AD0qaUDIME0F JRDtwAzWcSPB4Q48gwxomGqF6JFL1TQnBRJLBAIr8AXZ5ybb9zQgoAdp6SY6hBDuwSvIMIfltw9b wAz7gJKiYJXWdB1/qRAa+WG8Rl1gWRCUxAympArbSBFLZCsR2RDn5zTq+BGN+I/4Zw1moEPWoC1X CZh92BD7YGkgaWMeGUyCNFSFImeFBZkdIQqNEJcjEZD1AJEnWA9bQASNYAv1MC22IApbABylYjf7 QJxBUltT2FpiRW0GWUYz4H2xFSiVYxRS+JTlV5XdQEmZ6BBc6IWXZWXuIFwg/xWdrqkUogAAstkQ S6kwPlBJ7jAOhIeE9/aVHuEOjald0hmZP2E3pZIQp3IqHIQ07YCG1tkQgiiF0PmOHcEM7eSY+QkV tCgQ+DI7wXEqUbid7tedrvedvjgDEZBt5DmdVBEhuxBOgYmh7veI+9WRMfGYIioYafSZoTmjWriJ y7duL+Gi+tkUu1koYSOjKBqBgugDhKiMLKGjXzGh74MvgogrdYCZT6iiakheboek0TgXNoqKKWGl V1oXpmhbWmoSXNqlc8GOuMihJDGmZBoXbtCFyTgWhvgParqmcQECWbeGiNmaL0qndfqD+wc3GDGn fCoXC5h7nXKfjvagg6p5fv9KgIfqoOW5qIyaFci3VohaX5EqqZOqaHVQfXGCHiI4ewYhqJpaF4UK E/IVIIhKqqVqqo06WWqmqs2lqK3adXnGELKaqJlaq4DhLKmHebj6qLG2q7z6F+gjqtC3EG/DqsX6 EEn5rNAardIqQ9x3o7kXq5rDrM2aKCDmgd76reAaruF6R0+ToO2nrJ5Gq9t6Eae6E7HkXcCKrsO6 p+tKEe2qE9sUf60WrAWhrfUaEfe6E3GqgthKUOr6rxkRsH53q/LqrwgrEQq7aq86Eqk6PsT6sAk7 saiqsX0Vq46DsQfEsTwlstC4EPQKshnbk46HsjKjsj3HshtDsr0ks04VjDD/izo0qxID24Q364Nl UW/dx7A9ixIROxMCl5zxOrQnUbQwIVzetaHvZbNKa005mzIwF19SO7VMGxM5l2VZq7RbKxMo547n OrWZYxYvp3Era7YjEbY20bXJyrZtS09QSxOqyE6F2WYTNpCaJrduw2ciiRMq9iAtdnFJd2lR67dz q3jdCIRghmwMIWRRt7aK+z2wlpAnwTlRhl5TFmhVqxH2WLkE0WiYO1lgJo+He6ZeK7oh24Cl0bg8 lSNxthB0xrd697VDK2xCWLchBWiCpmt4m2Csa5n8Z4WB20uRBgBTihDLhrj7OrwdobvGy7umK6ej hlDeBZ2nZlufexGhO7zS/xuGsKuHXFJrM5AsmWBKi3eIu/ay0MsR4YsQpeu9CnRs/2BLiNq81FtP Bpm3YKUScVgd97Gu8Usg4+sR1CZy2PZKY9YQR2uuCzG4LOZiO1gbKwYhBFy8/Xe8LVG3Tuud9Osh 0VXBG+NjFFmrBXyIB2wSqpCgQDufoAtll6qHuDu6UBakZCqFxpdo84sRLTwnBfHAXybCpZm5NXwd JryjV3p9nyogoQpQPRwrUPNMH7y/8FgoTMSas3bE1iS7s6i1SBbFXnO1fzZkv8uzGwMimGK2LSfG GQG3PebEy2tUtTEqINCfYJuDKzxSaFWkr5gjohYBtqRiqDmGdSwQ6IgtyP+Axwhrdm4cqBm3ovJU vrYmEEVMsVzch9aCNhrJsob3yBgBxxRhbCPsDiLglXScxvDTiHYDs6YHyqa1t1KXwB6Ebb+wC0wE lDp7xCzpkvzSLjNQB8sDsgMIy8pEZqorErtQyDqbDgKYLLtQmdtaqMbcEFCHjNbqEDOMWJmsEPIT mA/brtU8f3d6EswAuSHVzQmBDI3QDe4gzc0asON8EDv7D4jgoVWQzaOszuvMF3Y5zZK4x/LUvfLE z37LtPNcIwTtvQYtt+Bzt09zyeHHwa9YWsWVi/q8z+8rL49Va/Eo0TEi0C3VZONpyYVpynaVEvBc lwkBzyh8mHLDEbCMYE3/M6Wi1qBMo7ypbBLuwcjHA6U93cgwvYQUvYyftVHo3Bi19SlIvdMlsQUR oJLjEIV3BdUFWqqSFI9WW9T1qFmZsDwg4F6nTARa3BhgTbYde4RgfRBbYAZEEKH/wEEB+q9Z/TQH SdRWfBCoJxFv/Q9tjZjBwUF01dd/vRILeRI9ugUR2spzTRCJDde8mtVlBNIOKNJbE9EQYZUIM9XJ VAURwkMDodlx/c0pQZJKTBHOstn7KKGffRqpPdp0PdT2bDQbNZRFyTVYRJRckwTFBwNxMBA+wEDK 05+CSBBmYDbBPRDfAAbFx9u3LXxHGUPTukIqFAe/jchLecfNs9q2gNxL//kKQjTdR4I0ks2/IgDB EHUHZomW2LeWFOSWZ5Im0ocFDNk8s3Q614FPWrk6ziMQaJAD1Icmb8km2xcABt6WA84mAj7f9b09 xsOVo7s6w9w8xoMLAD59C57ga1JAYXXFBEFJ6ds5JX0RDmsQkwkALo2r7ukDS2kLDRooBQECK76e IGEHCfAADeAF3tKfLE4Q3b3dMc7jNB4SHD5Yp0kQqjBM+KtXF/sQsJmeEiEK05QJq12RlYFLBCHl jVHlIhEMw7AMLAGbsI0tBbQFWiLmU020DZ0W6KROzelRZZ3eTa4SdtMNIgDXjWAGX20QdX7nVtHK im0Qu9nYAwHokE3ka/+OFkCX17p6siyxBTMAMhx0SAYB6TicFJaekR8G2Zmu5ivVET9M4gcrExz0 lGh4V6WOFanO1kVOEKu+tIluKVYW6ug9r6eNEj7g07kCpbWi61OR63LJ68Du6R3uNVN8VnM+E/9M lQmx7BzRDzTh7L5+Q/IS66YygSUOvtZOHX+X7dDb6pnVEt7+vuDuFZzhMwMRGi2rEuO+0eXeFavR Gv/xD7ExG+t+Eu2+0X247S3BGzHzD8ABgyWR7/q+72WRHMuhyylhegRf8H3ozNRBLdgh8GQ56g4P Ee/+FeAhHuRhLHmaEQ1/8dbE7y2hH/zhHx7vTqKe7CLvEBn/FRRyDhb/kvLhE8ss3/IuT/ItkSIg sCI3WDiQ6ug4j/E63+828u8GYUHirUK5ChEhP/QxXvQsISZkohBqkuEaLn1NHILrJI9PD/VRz+aL MhCx0cRLK6yzevNgD7BSzxKbIhDwEAfwwBrcQLRo3+i3vvbK2vYwcQ+i0YdjbxJNb+t6b5l8LxP8 cOkpC/SEX/iGHxcPtPAA9fWO75+HDxPPcN12j59qX/kHYQ3UegotNORbcQ7XrRxnj/eeXxGwWX1I AAjVB+WlXx+oL/ifQvmrvxmeQRupj6lCn/tXahu4D/yZIg8VURnDT/wBKOMWr/waUQ/QH/3SP/14 9bHODxLgWB/a/x5XfS0dv3/94B/+4j/+5F/+5r8T0X/+g4ovkqL+7v/+8B//8j//9F//9n//+J// +r///A8Q/wQOJFjQ4EGECRUuZNjQ4UOIESVOpFjR4kWMGTVu5NjR40eQIUWOJFnS5EmUKVWuZNnS 5UuYMWXOpFnT5k2cOXXu5NnT50+gNgMCADs= ------=_NextPart_000_0008_01C6762A.A5671CA0 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist ------=_NextPart_000_0008_01C6762A.A5671CA0--