SBAS475A June   2009  – January 2023 AMC6821-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Functional Block Diagram
    2. 8.2 Feature Description
      1. 8.2.1 ADC Converter
      2. 8.2.2 Temperature Sensor
        1. 8.2.2.1 Series Resistance Cancellation
        2. 8.2.2.2 Reading Temperature Data
        3. 8.2.2.3 Temperature Out-of-Range Detection
        4. 8.2.2.4 Remote Temperature Sensor Failure Detection
      3. 8.2.3 PWM Output
      4. 8.2.4 PWM Waveform Setting
      5. 8.2.5 Fan Speed Measurement
        1. 8.2.5.1 Tach-Data Register
          1. 8.2.5.1.1 Reading the Tach Data Register
          2. 8.2.5.1.2 RPM Measurement Rate
          3. 8.2.5.1.3 Select Number of Pulses/Revolution
          4. 8.2.5.1.4 Tach Mode Selection
          5. 8.2.5.1.5 Fan RPM Out-of-Range Detection
      6. 8.2.6 Fan Failure Detection
      7. 8.2.7 FAN-FAULT Pin
      8. 8.2.8 Fan Control
        1. 8.2.8.1 THERM Pin and External Hardware Control
          1. 8.2.8.1.1 THERM Pin as an Output
          2. 8.2.8.1.2 THERM Pin as an Input
        2. 8.2.8.2 Fan Spin-Up
        3. 8.2.8.3 Normal Fan Speed Control
          1. 8.2.8.3.1 Software DCY Control Mode
          2. 8.2.8.3.2 Software-RPM Control Mode (Fan Speed Regulator)
          3. 8.2.8.3.3 Auto Temperature Fan Mode
      9. 8.2.9 Interrupt
        1. 8.2.9.1 OVR Pin
        2. 8.2.9.2 SMBALERT Pin
        3. 8.2.9.3 SMBALERT Interrupt Behavior
        4. 8.2.9.4 Handling SMBALERT Interrupts
    3. 8.3 Device Functional Modes
    4. 8.4 Programming
      1. 8.4.1 SMBus Interface
        1. 8.4.1.1 Communication Protocols
      2. 8.4.2 SMBus Alert Response Address (ARA)
      3. 8.4.3 Power-On Reset and Start Operation
    5. 8.5 Register Map
      1. 8.5.1 Register Description
        1. 8.5.1.1 Device Configuration Registers
        2. 8.5.1.2 Device Status Registers
        3. 8.5.1.3 Fan Controller Registers
        4. 8.5.1.4 Temperature Data Registers
        5. 8.5.1.5 Temperature Limit Registers
          1. 8.5.1.5.1 Tach-Data Register
          2. 8.5.1.5.2 Tach Setting Register
          3. 8.5.1.5.3 Tach Low Limit Register
          4. 8.5.1.5.4 Tach High Limit Register
  9. 9 Application and Implementation
    1. 9.1 Power Supply Recommendations
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.4.2 SMBus Alert Response Address (ARA)

The alert response address is a feature of SMBus devices that allows an interrupting device to identify itself to the host when multiple devices issue simultaneous interrupts. The SMBALERT pin is an open-drain interrupt output pin. When the AMC6821-Q1 issues an interrupt request, the following procedure occurs:

  1. SMBALERT is pulled low.
  2. The bus master sends an alert response address or ARA (ARA = 0001100), and initiates a read operation (see Table 8-12).
  3. The AMC6821-Q1 responds to the ARA by sending its slave address back. The 7-bit device slave address is placed in the seven most significant bits of the byte; the last bit is '0'.
  4. The master receives the AMC6821-Q1 slave address and starts the interrupt service.
  5. If more than one device pulls the SMBus low, the highest priority (lowest slave address) device wins the communication right via standard arbitration during the slave address transfer (refer to the SMBus specification version 2.0 for details).
  6. To service the interrupt request of the AMC6821, the master must read the status register. Most interrupt source bits in the status registers are cleared after reading the status register, and are reasserted if the error condition still exists on the next monitoring cycle. The SMBALERT only clears if the interrupt has been resolved.
Table 8-12 ARA Operation
SALERT RESPONSE ADDRESSRDACKDATANACKP
0001100 var tempcontentStr='/Analog & Mixed-Signal/sensors/temperature sensors/digital temperature sensors'; var partNum ='AMC6821-Q1'; var contentStr = replaceSplChars( tempcontentStr )+ "/"+ partNum; var tiContentGroup = contentStr.replace("'",""); function replaceSplChars(content){ var myRegExp=new RegExp("™|®|™","gi"); content=content.replace(myRegExp,""); return content; } var tiProductPathID='/353/611/3181/'; var tiPageName = 'Literature reader-SBAS475A-en_US'; var tiDocType = 'Data Sheet'; var tiLibraryStore = new com.TI.tiLibrary.tiLibraryStore(); var tiLibraryViewerStore = tiLibraryStore.viewer_store; RiotControl.addStore(tiLibraryStore); var subRoutes = riot.route.create(); subRoutes("/document-viewer/*/datasheet/*\\?*#*", function(gpn, url, params, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + gpn + "/datasheet/" + url + "#" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/datasheet/*#*", function(gpn, url, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + gpn + "/datasheet/" + url + "#" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/datasheet/*", function(gpn, url) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + gpn + "/datasheet/" + url, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/*/datasheet/*\\?*#*", function(locale, gpn, url, params, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + locale + "/" + gpn + "/datasheet/" + url + "#" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/*/datasheet/*#*", function(locale, gpn, url, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + locale + "/" + gpn + "/datasheet/" + url + "#" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/*/datasheet/*", function(locale, gpn, url) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + locale + "/" + gpn + "/datasheet/" + url, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/datasheet#*/*", function(gpn, url, fragment) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + gpn + "/datasheet#" + url + "/" + fragment, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/*/datasheet#*/*", function(locale, gpn, url, fragment) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + locale + "/" + gpn + "/datasheet#" + url + "/" + fragment, toc: true, set_content: true }); }); subRoutes("/document-viewer/lit/html/*", function(litnum) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/lit/html/" + litnum, toc: true, set_content: true }); }); subRoutes("/document-viewer/lit/html/*/*\\?*#*", function(litnum, url, params, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/lit/html/" + litnum + "/" + url + "#" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/lit/html/*/*#*", function(litnum, url, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/lit/html/" + litnum + "/" + url + "#" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/lit/html/*#*/*", function(litnum, url, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/lit/html/" + litnum + "#" + url + "/" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/lit/html/*#*/*", function(locale, litnum, url, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + locale + "/lit/html/" + litnum + "#" + url + "/" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/lit/html/*/*", function(litnum, url) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/lit/html/" + litnum + "/" + url, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/lit/html/*/*\\?*#*", function(locale, litnum, url, params, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + locale + "/lit/html/" + litnum + "/" + url + "#" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/lit/html/*/*#*", function(locale, litnum, url, anchor) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + locale + "/lit/html/" + litnum + "/" + url + "#" + anchor, toc: true, set_content: true }); }); subRoutes("/document-viewer/*/lit/html/*/*", function(locale, litnum, url) { RiotControl.trigger("ti_library_open_viewer", { document: tiLibraryViewerStore.document, documentLocale: tiLibraryViewerStore.documentLocale, url: "/document-viewer/" + locale + "/lit/html/" + litnum + "/" + url, toc: true, set_content: true }); }); var compose_url = function(q) { //URL format: scheme:[//[user[:password]@]host[:port]][/path][?query][#fragment] var tempUrl = q.url.replace("//www.ti.com/", ""); var url = tempUrl.replace("//www.ti.com/", ""); if (q.search != null) { var params = ""; var hash = ""; var url_parts = url.split('#'); if (url_parts.length == 2) { url = url_parts[0]; hash = url_parts[1]; } var param_parts = url.split('?'); if (param_parts.length == 2) { url = param_parts[0]; var parsed_params = param_parts[1].split('&'); var keyword_param_found = false; for (var i = 0; i < parsed_params.length; i++) { if (parsed_params[i].indexOf('search=') == 0) { keyword_param_found = true; parsed_params[i] = 'search=' + q.search; } } if (!keyword_param_found) { parsed_params.push('search=' + q.search); } params = parsed_params.join('&'); } else { params = 'search=' + q.search; } if (params > "") { url = url + '?' + params; } if (hash > "") { url = url + '#' + hash; } } return url; }; tiLibraryViewerStore.compose_url_route = function(location, q) { return compose_url(q); }; tiLibraryViewerStore.compute_content_href = function(href, url) { return url; }; tiLibraryViewerStore.compose_topic_url = function(location, q) { return compose_url(q); }; tiLibraryViewerStore.important_notice_url = "//www.ti.com/document-viewer/AMC6821-Q1/datasheet/important_notice#ImpNotice001"; var ods_reader = riot.mount('ti-library-viewer', { store: tiLibraryStore.list_store, viewerstore: tiLibraryViewerStore }); riot.route.base('/'); riot.route.start(true); compute_document_locale = function(docName) { var locale = 'en_US'; if (docName) { if (docName.toLowerCase().indexOf('z')===0) { locale = 'zh_CN'; } else if (docName.toLowerCase().indexOf('j') == 0) { locale = 'ja_JP'; } } return locale; } open_reader = function() { var path = window.location.pathname.split('/'); var path_minus_filename = ''; for (var i = 0; i < path.length - 1; i++) { if (i == 0 && path[i] == '') { console.log("double slashes found in beginning of document path; treating document path as local machine path"); continue; } path_minus_filename += "/" + path[i]; } RiotControl.trigger("ti_library_open_viewer", { documentLocale: compute_document_locale( "SBAS475A"), document: { href: path_minus_filename, lit_num: "SBAS475A", doc_type: "Data Sheet", show_toc: "true", translated_doc_type: "Data sheet", gpn: "AMC6821-Q1", title: "AMC6821-Q1 Intelligent Temperature Monitor and PWM Fan Controller", disclaimer: "", product: "//www.ti.com/product/AMC6821-Q1", email: 'mailto:?subject=AMC6821-Q1 Datasheet&body=http://www.ti.com/document-viewer/AMC6821-Q1/datasheet', download: '//www.ti.com/lit/gpn/AMC6821-Q1', tistore: '//store.ti.com/Search.aspx?k=AMC6821-Q1&pt=-1', productstatusdescription: 'PRODUCTION DATA' }, url: "/document-viewer/AMC6821-Q1/datasheet/GUID-23535421-98F2-4F32-A512-9D0861610E83", prepopulated: true, modalOptions: { dismissible: false } }); } open_reader();