Datasheet ADT7312 (Analog Devices) - 10

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ADT7312 Data Sheet ONE-SHOT MODE CT and INT Operation in One-Shot Mode
When one-shot mode is enabled, the ADT7312 immediately Figure 12 illustrates the operation of the CT pin in one-shot completes a conversion and then goes into shutdown mode. mode when the TCRIT overtemperature limit is exceeded. Note The one-shot mode is useful when one of the circuit design that in interrupt mode, a read from any register resets the CT priorities is to reduce power consumption. and INT pins. (For more information about interrupt mode and To enable one-shot mode, set Bits[6:5] of the configuration reg- comparator mode, see the Undertemperature and Overtemperature ister (Register Address 0x01) to 01. After writing to the operation Detection section.) mode bits (Bits[6:5]), wait at least 240 ms before reading back the If the INT pin is configured for comparator mode and the temperature from the temperature value register (see Figure 11). temperature falls below the THIGH − THYST value or exceeds the This delay ensures that the ADT7312 has adequate time to power TLOW + THYST value, a write to the operation mode bits of the up and complete a conversion. configuration register (Register Address 0x01, Bits[6:5] = 01) To obtain an updated temperature conversion, reset Bits[6:5] resets the INT pin. of the configuration register to 01. If the CT pin is configured for comparator mode and the temperature falls below the TCRIT − THYST value, a write to the operation mode bits of the configuration register (Register Address 0x01, Bits[6:5] = 01) resets the CT pin (see Figure 12). When using one-shot mode, ensure that the refresh rate is appropriate to the application being used.
CS DIN 0x08 0x20 WAIT 240ms MINIMUM FOR CONVERSION TO FINISH DATA DOUT SCLK
012 06791- Figure 11. Typical SPI One-Shot Write to Configuration Register Followed by a Read from the Temperature Value Register Rev. A | Page 10 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 Pad Configuration and Function Descriptions Die Bond Pad Coordinates Typical Performance Characteristics Theory of Operation Circuit Description Converter Architecture Normal Mode (Continuous Conversion Mode) One-Shot Mode CT and INT Operation in One-Shot Mode 1 SPS Mode Shutdown Mode 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 Interface SPI Command Byte Writing Data Reading Data Interfacing to DSPs or Microcontrollers Resetting the Serial Interface INT and CT Outputs Undertemperature and Overtemperature Detection Comparator Mode Interrupt Mode Redundant Critical Generator 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