{"id":8601,"date":"2026-06-29T06:56:27","date_gmt":"2026-06-29T06:56:27","guid":{"rendered":"https:\/\/materialparts.com\/ad549jhz\/"},"modified":"2026-06-29T06:56:27","modified_gmt":"2026-06-29T06:56:27","slug":"ad549jhz","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/ad549jhz\/","title":{"rendered":"AD549JHZ"},"content":{"rendered":"

\u4ea7\u54c1\u6982\u89c8<\/h2>\n

The Analog Devices AD549JHZ is an ultra-low input bias current monolithic electrometer operational amplifier with maximum input bias current of 60 fA. Packaged in a TO-99 metal can, it provides 1 MHz gain-bandwidth product and is specifically designed for electrometer, photodiode, and high-impedance source applications requiring femtoampere-level input current.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n
\u8f93\u5165\u504f\u7f6e\u7535\u6d41<\/td>\n60 fA max<\/td>\n<\/tr>\n
\u8f93\u5165\u5931\u8c03\u7535\u538b<\/td>\n0.5 mV max<\/td>\n<\/tr>\n
GBW<\/td>\n1 MHz<\/td>\n<\/tr>\n
\u538b\u6446\u7387<\/td>\n1.5 V\/\u00b5s<\/td>\n<\/tr>\n
\u7535\u6e90\u7535\u538b<\/td>\n\u00b15 V to \u00b118 V<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nTO-99 (8-lead)<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • Ultra-low input bias current: 60 fA max<\/li>\n
  • Low input offset voltage: 0.5 mV max<\/li>\n
  • Guard pin for input leakage protection<\/li>\n
  • TO-99 metal can for low leakage<\/li>\n
  • 1 MHz gain-bandwidth product<\/li>\n
  • Operates from \u00b15 V to \u00b118 V supplies<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • Electrometer and picoammeter circuits<\/li>\n
    • Photodiode and photomultiplier amplifiers<\/li>\n
    • Ion-selective electrode measurements<\/li>\n
    • Coulombmetry and charge amplifiers<\/li>\n
    • High-impedance transducer interfaces<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The Analog Devices AD549JHZ is an ultra-low input bias current monolithic electrometer operational amplifier with maximum input bias current of 60 fA. Packaged in a TO-99 metal can, it provides 1 MHz gain-bandwidth product and is specifically designed for electrometer, photodiode, and high-impedance source applications requiring femtoampere-level input current. Key Specifications Input Bias […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19,13],"tags":[],"chip_brand":[165],"class_list":["post-8601","post","type-post","status-publish","format-standard","hentry","category-analog-linear-ics","category-integrated-circuits-ics","chip_brand-adi"],"acf":{"brief_explanation":"Ultra-low Ibias electrometer op-amp, 60fA max, 1MHz GBW, TO-99 metal can, \u00b15V to \u00b118V","date_code":"","package_case":"TO-99 (8-lead metal can)","in_stock":3215,"datasheet":"https:\/\/www.analog.com\/media\/en\/technical-documentation\/data-sheets\/AD549.pdf","price":"$12.50 @ 1ku","product_introduction":"The AD549JHZ from Analog Devices is a monolithic electrometer operational amplifier featuring the lowest input bias current available in a standard op-amp package. With a maximum input bias current of only 60 fA at 25\u00b0C, the AD549 is specifically designed for applications requiring extremely high input impedance. The device uses a JFET input stage with proprietary dielectric isolation technology to achieve its ultra-low input current specifications. The TO-99 metal can package includes a guard pin that allows the user to protect the high-impedance input node from PCB leakage currents.","working_principle":"The AD549 achieves its ultra-low input bias current through a JFET input stage fabricated using dielectric isolation technology. The input JFETs are electrically isolated from the substrate by a layer of silicon dioxide, eliminating the parasitic leakage paths that exist in conventional junction-isolated devices. The guard ring structure, accessible via the guard pin, surrounds the input pins on the PCB and is driven at the same potential as the input, minimizing surface leakage currents. The internal compensation provides unity-gain stability, while the output stage is capable of driving 10 kOhm loads to within 2 V of the supply rails.","pin_description":"\n
      Pin<\/th>Name<\/th>Type<\/th>Function<\/th><\/tr>\n
      1<\/td>NULL<\/td>Offset Adjust<\/td>Offset null adjustment<\/td><\/tr>\n
      2<\/td>-IN<\/td>Input<\/td>Inverting input<\/td><\/tr>\n
      3<\/td>+IN<\/td>Input<\/td>Non-inverting input<\/td><\/tr>\n
      4<\/td>V-<\/td>Power<\/td>Negative supply voltage<\/td><\/tr>\n
      5<\/td>NULL<\/td>Offset Adjust<\/td>Offset null adjustment<\/td><\/tr>\n
      6<\/td>OUTPUT<\/td>Output<\/td>Amplifier output<\/td><\/tr>\n
      7<\/td>V+<\/td>Power<\/td>Positive supply voltage<\/td><\/tr>\n
      8<\/td>GUARD<\/td>Guard<\/td>Guard ring connection for input protection<\/td><\/tr>\n<\/table>","application_scenarios":"
        \n
      • Picoammeter and electrometer front-end amplifiers<\/li>\n
      • Photomultiplier tube (PMT) current measurement<\/li>\n
      • pH and ion-selective electrode interfacing<\/li>\n
      • Radiation detector charge amplifiers<\/li>\n
      • High-impedance transducer signal conditioning<\/li>\n<\/ul>","alternative_models":"\n
        Manufacturer<\/th>Part Number<\/th>Ibias Max<\/th>Package<\/th>Notes<\/th><\/tr>\n
        ADI<\/td>AD549KH<\/td>60 fA<\/td>TO-99<\/td>Same family, tighter spec<\/td><\/tr>\n
        TI<\/td>LMC6001AIN<\/td>25 fA<\/td>DIP-8<\/td>Lower Ibias alternative<\/td><\/tr>\n
        ADI<\/td>ADA4530-1<\/td>20 fA<\/td>SOIC-8<\/td>Modern electrometer amp<\/td><\/tr>\n
        Keystone<\/td>2N5458<\/td>N\/A<\/td>TO-92<\/td>Discrete JFET approach<\/td><\/tr>\n<\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/8601","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/comments?post=8601"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/8601\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=8601"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=8601"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=8601"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=8601"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}