ADT7320, ADT7420 - Requirements to setup the ADT7320/ADT7420

Question What additional components do I require to setup the ADT7320/ADT7420? Answer Both parts require a 0.1uf ceramic and 10uf tantalum decoupling capacitors. The interrupt and critical limit pins will also require 10kΩ pull-up resistors. The ADT7420 will also require pull-up resistors on the SDA and SDL line of the I²C bus.

What is the lifetime of the ADT7320?

Question What is the lifetime of the ADT7320? (Stauts of 08_2013) Answer We guarantee the ADT7320 with a lifetime of at least 10 years, provided it operates according to the specifications outlined in the datasheet.

ADT7320, ADT7420 - Temperatur reading optiions

Question Why do I have an option between 13 and 16 bit temperature readings? Answer In 16-bit mode the user has a resolution of 0.0078°C but in 13-bit mode the resolution is only 0.0625°C. However in 13-bit mode the 3 LSB’s of the temperature register also contain the T_High, T_Low and T_Crit register flags. If an interrupt is triggered it will appear in these bits. This can be useful in continuous read mode where the master is only inputting a clock to receive a temperature reading and not continuously polling over limit registers or monitoring interrupt pins.

Question Does the ADT7X20 need to be calibrated? Answer No user calibration is required with these sensors because ADI pre-calibrates all devices using our high accuracy test solution. Because each device leaving the factory is fully calibrated, all errors involved in measuring and digitizing the temperature value are included in the sensor’s accuracy specifications.

ADT7320, ADT7420 - Communication with ADT7x20

Question How do I communicate with the ADT7320 and ADT7420? Answer The ADT7320 has a SPI 4-wire interface and the ADT7420 has an I²C 2-wire interface. The sensors will typically complete a conversion every 240ms and update the temperature register. The part has 4 operating modes: Continuous conversion, one-shot mode, 1 sample per second and shutdown. These modes can be selected in the configuration register.