{"product_id":"build-an-instrumentation-amplifier-with-picoamp-level-input-bias-current","title":"Build an Instrumentation Amplifier with Picoamp-Level Input Bias Current","description":"\u003cp\u003eThe LT1079 draws very little supply current while still delivering low offset voltage and low noise. This makes the module well-suited to battery-powered instrumentation and sensor front-ends where both precision and low power draw matter.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eSpecs and Features\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSupply voltage: 9 V DC\u003c\/li\u003e\n\u003cli\u003eOutput range: 4 mV to 8.2 V\u003c\/li\u003e\n\u003cli\u003eKey IC: LT1079 micropower quad op amp\u003c\/li\u003e\n\u003cli\u003eGain: (1 + 2R3\/RG) × R9\/R2 = 100\u003c\/li\u003e\n\u003cli\u003eInput bias current: typically less than 150 pA\u003c\/li\u003e\n\u003cli\u003eInput resistance: 3R = 30 MΩ\u003c\/li\u003e\n\u003cli\u003eGain bandwidth: 1.8 MHz\u003c\/li\u003e\n\u003cli\u003eOnboard power LED\u003c\/li\u003e\n\u003cli\u003eHeader connectors for input, output, and power\u003c\/li\u003e\n\u003cli\u003ePCB dimensions: 36.99 mm x 16.19 mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eHow It Works\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe LT1079 is a micropower quad op amp in a standard 16-pin package. It is optimized for 5 V single-supply operation, though ±15 V operation is also specified. Most micropower op amps sacrifice precision, noise, speed, or output drive to save current. In contrast, the LT1079 cuts supply current without sacrificing performance.\u003c\/p\u003e\n\u003cp\u003eThe LT1079 achieves the lowest offset voltage of any dual or quad non-chopper-stabilized op amp. Its offset current, noise, slew rate, and gain bandwidth product are two to ten times better than earlier micropower models. Its voltage noise 1\/f corner sits at 0.7 Hz—at least three times lower than any monolithic op amp. This provides low-frequency noise performance typically seen only in high-current devices.\u003c\/p\u003e\n\u003cp\u003eThe device can run from a single supply as low as one lithium cell or two Ni-Cad batteries. Its input range extends below ground. While sinking current, its all-NPN output stage swings within a few millivolts of ground, eliminating the need for power-consuming pull-down resistors.\u003c\/p\u003e\n\u003cp\u003eOn this board, three internal op amps form the instrumentation amplifier signal path. Two serve as input buffers, followed by a difference amplifier that sets an overall gain of 100. The fourth op amp combines with resistors R10, R17, and R18 to form a bias current cancellation loop, removing input bias current before it introduces sensor errors. Bridge resistors R1, R4, R5, R12, R13, and R16 allow the input stage to interface directly with resistive bridge sensors.\u003c\/p\u003e","brand":"dotfry","offers":[{"title":"Default Title","offer_id":47192823300268,"sku":"D108","price":22.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0757\/6436\/7532\/files\/D108.png?v=1789208424","url":"https:\/\/dotfry.com\/products\/build-an-instrumentation-amplifier-with-picoamp-level-input-bias-current","provider":"dotfry","version":"1.0","type":"link"}