Datasheet ADT7311 (Analog Devices) - 20

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ADT7311 Data Sheet INT AND CT OUTPUTS
The INT and CT pins are open-drain outputs, and both pins
Comparator Mode
require a 10 kΩ pull-up resistor to VDD. The ADT7311 must be In comparator mode, the INT pin returns to its inactive status fully powered up to VDD before reading INT and CT data. when the temperature drops below the THIGH − THYST limit or rises above the TLOW + THYST limit.
UNDERTEMPERATURE AND OVERTEMPERATURE DETECTION
Putting the ADT7311 into shutdown mode does not reset the INT state in comparator mode. The INT and CT pins have two undertemperature/over- temperature modes: comparator mode and interrupt mode.
Interrupt Mode
The interrupt mode is the default power-up overtemperature In interrupt mode, the INT pin goes inactive when any ADT7311 mode. The INT output pin becomes active when the tempera- register is read. When the INT pin is reset, it goes active again ture is greater than the temperature stored in the THIGH setpoint only when the temperature is greater than the temperature register or less than the temperature stored in the TLOW setpoint stored in the THIGH setpoint register or less than the temperature register. How this pin reacts after this event depends on the stored in the TLOW setpoint register. overtemperature mode selected. Placing the ADT7311 into shutdown mode resets the INT pin Figure 19 illustrates the comparator and interrupt modes for in the interrupt mode. events exceeding the THIGH limit with both pin polarity settings. Figure 20 illustrates the comparator and interrupt modes for events exceeding the TLOW limit with both pin polarity settings.
TEMPERATURE 82°C 81°C 80°C THIGH 79°C 78°C 77°C 76°C 75°C THIGH – THYST 74°C 73°C INT PIN (COMPARATOR MODE) POLARITY = ACTIVE LOW INT PIN (INTERRUPT MODE) POLARITY = ACTIVE LOW INT PIN (COMPARATOR MODE) POLARITY = ACTIVE HIGH INT PIN (INTERRUPT MODE) POLARITY = ACTIVE HIGH TIME
0 02 0-
READ READ READ
05 09 Figure 19. INT Output Temperature Response Diagram for THIGH Overtemperature Events Rev. 0 | Page 20 of 24 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION PRODUCT HIGHLIGHTS FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS SPI TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CIRCUIT INFORMATION CONVERTER DETAILS TEMPERATURE MEASUREMENT ONE-SHOT MODE 1 SPS MODE CT and INT Operation in One-Shot Mode SHUTDOWN FAULT QUEUE TEMPERATURE DATA FORMAT TEMPERATURE CONVERSION FORMULAS 16-Bit Temperature Data Format 13-Bit Temperature Data Format 10-Bit Temperature Data Format 9-Bit Temperature Data Format REGISTERS STATUS REGISTER CONFIGURATION REGISTER TEMPERATURE VALUE REGISTER ID REGISTER TCRIT SETPOINT REGISTER THYST SETPOINT REGISTER THIGH SETPOINT REGISTER TLOW SETPOINT REGISTER SERIAL PERIPHERAL INTERFACE SPI COMMAND BYTE WRITING DATA READING DATA INTERFACING TO DSPs OR MICROCONTROLLERS SERIAL INTERFACE RESET INT AND CT OUTPUTS UNDERTEMPERATURE AND OVERTEMPERATURE DETECTION Comparator Mode Interrupt Mode APPLICATIONS INFORMATION THERMAL RESPONSE TIME SUPPLY DECOUPLING POWERING FROM A SWITCHING REGULATOR TEMPERATURE MONITORING QUICK GUIDE TO MEASURING TEMPERATURE OUTLINE DIMENSIONS ORDERING GUIDE AUTOMOTIVE PRODUCTS