{"id":3649,"date":"2026-06-07T13:03:16","date_gmt":"2026-06-07T13:03:16","guid":{"rendered":"https:\/\/materialparts.com\/max1681esat\/"},"modified":"2026-06-07T13:03:16","modified_gmt":"2026-06-07T13:03:16","slug":"max1681esat","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/max1681esat\/","title":{"rendered":"MAX1681ESA+T"},"content":{"rendered":"

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

The MAX1681ESA+T from Analog Devices (formerly Maxim) is a 125mA, charge-pump voltage inverter in an 8-pin SOIC package. Operating from 2.0V to 5.5V input, it generates a negative output voltage with only two external capacitors, requiring no inductors. Switching at 125kHz or 500kHz, it achieves up to 98% conversion efficiency.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
\u62d3\u6251\u7ed3\u6784<\/td>\nCharge-Pump Voltage Inverter<\/td>\n<\/tr>\n
\u8f93\u5165\u7535\u538b<\/td>\n2.0V to 5.5V<\/td>\n<\/tr>\n
\u8f93\u51fa\u7535\u6d41<\/td>\n125 mA (max)<\/td>\n<\/tr>\n
\u5f00\u5173\u9891\u7387<\/td>\n125 kHz \/ 500 kHz (selectable)<\/td>\n<\/tr>\n
Conversion Efficiency<\/td>\nUp to 98%<\/td>\n<\/tr>\n
Output Resistance<\/td>\n6 Ohm (typ @ 500kHz)<\/td>\n<\/tr>\n
\u9759\u6001\u7535\u6d41<\/td>\n500 uA (typ @ 500kHz)<\/td>\n<\/tr>\n
\u5173\u673a\u7535\u6d41<\/td>\n1 uA<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-40 to +85 C<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nSOIC-8<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • Inverts input voltage without inductors<\/li>\n
  • Only 2 external capacitors required<\/li>\n
  • 125mA output current capability<\/li>\n
  • Pin-selectable 125kHz or 500kHz switching<\/li>\n
  • Up to 98% conversion efficiency<\/li>\n
  • 6 Ohm typical output resistance at 500kHz<\/li>\n
  • Shutdown mode with 1uA current<\/li>\n
  • +\/-1% output voltage accuracy with low ESR caps<\/li>\n
  • Drop-in replacement for ICL7660\/S7660<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • Negative supply generation for op-amps<\/li>\n
    • LCD contrast control<\/li>\n
    • RS-232 negative rail generation<\/li>\n
    • Instrumentation dual-supply from single rail<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The MAX1681ESA+T from Analog Devices (formerly Maxim) is a 125mA, charge-pump voltage inverter in an 8-pin SOIC package. Operating from 2.0V to 5.5V input, it generates a negative output voltage with only two external capacitors, requiring no inductors. Switching at 125kHz or 500kHz, it achieves up to 98% conversion efficiency. Key Specifications Topology […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,32],"tags":[],"chip_brand":[165],"class_list":["post-3649","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-low-dropout-regulators-ldo","chip_brand-adi"],"acf":{"brief_explanation":"125mA charge-pump inverter, 2-5.5V, 125\/500kHz, SOIC-8, no inductor","date_code":"","package_case":"SOIC-8 (4.9 x 3.9 x 1.5 mm)","in_stock":7522,"datasheet":"https:\/\/www.analog.com\/media\/en\/technical-documentation\/data-sheets\/MAX1681.pdf","price":"$2.45 @ 1ku","product_introduction":"The MAX1681ESA+T from Analog Devices is a 125mA charge-pump voltage inverter that converts a positive input voltage (2.0-5.5V) to a corresponding negative output using only two external capacitors. The ESA suffix denotes SOIC-8 package, +T indicates tape and reel. Pin-selectable switching frequency (125kHz or 500kHz) allows trade-off between output ripple and capacitor size. With 6 Ohm typical output resistance at 500kHz and up to 98% efficiency, it provides a compact inductor-free negative supply solution for op-amp biasing, LCD contrast control, and RS-232 negative rail generation.","working_principle":"The MAX1681 operates through three subsystems: (1) Charge-Pump Inverter: A switched-capacitor circuit uses two phases. During Phase 1, the flying capacitor (C1) charges from VIN through internal switches. During Phase 2, C1 is connected with its positive terminal to GND and negative terminal to the output, transferring charge to the output capacitor (C2) and producing -VIN at the output. (2) Frequency Selection: The FC pin selects between 125kHz (FC=GND) for lower switching noise and 500kHz (FC=VIN or floating) for smaller capacitors and lower output resistance. Higher frequency reduces the output impedance from 20 Ohm to 6 Ohm. (3) Shutdown: Driving SHDN low disables the oscillator and reduces supply current to 1uA.","pin_description":"
      Pin<\/th>Name<\/th>Type<\/th>Description<\/th><\/tr>
      1<\/td>FC<\/td>Input<\/td>Frequency control (GND=125kHz, V+=500kHz)<\/td><\/tr>
      2<\/td>C1+<\/td>Power<\/td>Flying capacitor positive terminal<\/td><\/tr>
      3<\/td>GND<\/td>Power<\/td>Ground<\/td><\/tr>
      4<\/td>C1-<\/td>Power<\/td>Flying capacitor negative terminal<\/td><\/tr>
      5<\/td>OUT<\/td>Output<\/td>Negative output voltage<\/td><\/tr>
      6<\/td>LV<\/td>Input<\/td>Low-voltage mode (connect to OUT for Vin<3V)<\/td><\/tr>
      7<\/td>SHDN<\/td>Input<\/td>Shutdown (active low)<\/td><\/tr>
      8<\/td>V+<\/td>Power<\/td>Positive supply input (2.0-5.5V)<\/td><\/tr><\/table>","application_scenarios":"
      • Generating -5V from +5V for dual-supply op-amp circuits without inductors<\/li>
      • LCD panel negative contrast voltage with 500kHz mode for compact capacitors<\/li>
      • RS-232 negative rail from single +3.3V supply with 125mA drive<\/li>
      • Portable instrument dual-rail supply using only 2 external capacitors<\/li><\/ul>","alternative_models":"
        Model<\/th>Manufacturer<\/th>Iout<\/th>Frequency<\/th>Notes<\/th><\/tr>
        ICL7660SIBA<\/td>Renesas<\/td>40mA<\/td>10kHz<\/td>Lower current, lower cost<\/td><\/tr>
        LM27762DSGR<\/td>TI<\/td>250mA<\/td>2MHz<\/td>Regulated LDO output<\/td><\/tr>
        TPS60400DBVR<\/td>TI<\/td>60mA<\/td>50kHz<\/td>Smaller package<\/td><\/tr>
        MAX828ESA+T<\/td>ADI<\/td>50mA<\/td>12kHz<\/td>SOT-23 package<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/3649","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=3649"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/3649\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=3649"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=3649"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=3649"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=3649"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}