The MAX31865ATP from Maxim Integrated (now Analog Devices) is an RTD-to-digital converter in a TQFN-20 package. It simplifies precision temperature measurement using PT100\/PT1000\/PT500 RTD sensors with 15-bit resolution and SPI interface.<\/p>\n
| RTD Type<\/td>\n | PT100, PT1000, PT500<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Resolution<\/td>\n | 15-bit (0.03C for PT100)<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Accuracy<\/td>\n | +\/-0.5C (RTD accuracy dependent)<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Interface<\/td>\n | SPI (up to 5MHz)<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Excitation Current<\/td>\n | Programmable (0.5mA, 1mA, 2mA)<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Temperatura de funcionamiento<\/td>\n | -40C to +125C<\/td>\n<\/tr>\n<\/table>\nCaracter\u00edsticas<\/h2>\nAplicaciones<\/h2>\nProduct Overview The MAX31865ATP from Maxim Integrated (now Analog Devices) is an RTD-to-digital converter in a TQFN-20 package. It simplifies precision temperature measurement using PT100\/PT1000\/PT500 RTD sensors with 15-bit resolution and SPI interface. Key Specifications RTD Type PT100, PT1000, PT500 Resolution 15-bit (0.03C for PT100) Accuracy +\/-0.5C (RTD accuracy dependent) Interface SPI (up to 5MHz) […]<\/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":[13,38],"tags":[],"chip_brand":[165],"class_list":["post-7226","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-static-random-access-memory-sram","chip_brand-adi"],"acf":{"brief_explanation":"RTD-to-digital converter, PT100\/PT1000, 15-bit, SPI, TQFN-20, 2\/3\/4-wire, fault detect","date_code":"","package_case":"TQFN-20 (5.00 x 5.00 x 0.80 mm, 0.65mm pitch, exposed pad)","in_stock":8971,"datasheet":"https:\/\/www.analog.com\/media\/en\/technical-documentation\/data-sheets\/MAX31865.pdf","price":"$5.50 @ 1ku","product_introduction":"The MAX31865ATP from Maxim Integrated (now Analog Devices) is a dedicated RTD-to-digital converter that simplifies precision temperature measurement using platinum RTD sensors. The device integrates a precision excitation current source, a 15-bit delta-sigma ADC, and all necessary signal conditioning to convert the RTD resistance directly to a digital value accessible via SPI. Supporting PT100, PT500, and PT1000 RTD types with 2-wire, 3-wire, and 4-wire connection configurations, the device accommodates various sensor installations from simple to high-precision. The programmable excitation current (0.5mA, 1mA, or 2mA) optimizes the voltage drop across the RTD for the ADC range while minimizing self-heating. The 15-bit ADC provides 0.03C resolution for PT100 sensors, enabling precise temperature control and monitoring. An internal reference resistor sets the conversion ratio, and the SPI interface (up to 5MHz) provides easy readout of the RTD resistance ratio. Built-in fault detection circuitry identifies open or shorted RTD connections, RTD out-of-range conditions, and reference resistor faults, providing diagnostic information for system reliability.","working_principle":"The MAX31865ATP uses a ratiometric measurement technique for RTD-to-digital conversion. (1) Excitation: A programmable precision current source drives current through the RTD sensor. The current also flows through a precision reference resistor (RREF) connected between the RTDI and RTDIN- pins. (2) Ratiometric ADC: The delta-sigma ADC measures the voltage across the RTD (RTDIN+ to RTDIN-) and the voltage across the reference resistor (REFIN+ to REFIN-). Since both voltages are proportional to the same excitation current, the ratio RTD\/RREF is independent of the exact current value. This eliminates errors from excitation current drift. (3) Conversion: The 15-bit ADC provides a digital output proportional to the RTD resistance. The RTD resistance is calculated as RRTD = (ADC_Code \/ 2^15) x RREF. Temperature is then derived from the RTD resistance using the Callendar-Van Dusen equation or a lookup table. (4) Wire Compensation: For 3-wire RTDs, the device measures the lead resistance during one phase and compensates. For 4-wire RTDs, Kelvin sensing eliminates lead resistance effects entirely. (5) Fault Detection: The device monitors for open RTD (no current flow), shorted RTD (zero resistance), and reference resistor faults, reporting these via the fault register.","pin_description":"
|