Datasheet ADT7411 (Analog Devices) - 9

link to page 10
Data Sheet ADT7411 TERMINOLOGY Relative Accuracy Long-Term Temperature Drift
Relative accuracy or integral nonlinearity (INL) is a measure of This is a measure of the change in temperature error with the the maximum deviation, in LSBs, from a straight line passing passage of time. It is expressed in degrees Celsius. The concept through the endpoints of the ADC transfer function. A typical of long-term stability has been used for many years to describe INL vs. code plot can be seen in Figure 10. by what amount an IC’s parameter would shift during its lifetime. This is a concept that has been typically applied to both
Total Unadjusted Error (TUE)
voltage references and monolithic temperature sensors. Total unadjusted error is a comprehensive specification that Unfortunately, ICs cannot be evaluated at room temperature includes the sum of the relative accuracy error, gain error, and (25°C) for 10 years or so to determine this shift. As a result, offset error under a specified set of conditions. manufacturers typical y perform accelerated lifetime testing of
Offset Error
ICs by operating ICs at elevated temperatures (between 125°C This is a measure of the offset error of the ADC. It can be and 150°C) over a shorter period (typical y between 500 hours negative or positive. It is expressed in mV. and 1,000 hours). Because of this operation, the lifetime of an IC is significantly accelerated due to the increase in rates of
Gain Error
reaction within the semiconductor material. This is a measure of the span error of the ADC. It is the deviation in slope of the actual ADC transfer characteristic
DC Power Supply Rejection Ratio (PSRR)
from the ideal expressed as a percentage of the ful -scale range. The power supply rejection ratio (PSRR) is defined as the ratio of the power in the ADC output at ful -scale frequency f to the
Offset Error Drift
power of a 100 mV sine wave applied to the VDD supply of This is a measure of the change in offset error with changes in frequency fs. temperature. It is expressed in ppm of ful -scale range/°C. PSRR (dB) = 10 log(Pf/Pfs)
Gain Error Drift
where: This is a measure of the change in gain error with changes in temperature. It is expressed in ppm of ful -scale range/°C. Pf is the power at frequency f in ADC output. Pfs is the power at frequency fs coupled into the VDD supply.
Round Robin
This term describes the ADT7411 cycling through the available measurement channels in sequence, taking a measurement on each channel. Rev. C | Page 9 of 36 Document Outline Features Applications Pin Configuration General Description Revision History Specifications Functional Block Diagram Absolute Maximum Ratings ESD Caution Pin Configuration and Functional Descriptions Terminology Typical Performance Characteristics Theory of Operation Power-Up Calibration Conversion Speed Functional Description Analog Inputs Single-Ended Inputs Converter Operation ADC Transfer Function Analog Input ESD Protection AIN Interrupts Functional Description—Measurement Temperature Sensor VDD Monitoring On-Chip Reference Round Robin Measurement Single-Channel Measurement Temperature Measurement Method Internal Temperature Measurement External Temperature Measurement Layout Considerations Temperature Value Format Interrupts ADT7411 Registers Interrupt Status 1 Register (Read-Only) [Address = 00h] Interrupt Status 2 Register (Read-Only) [Address = 01h] Internal Temperature Value/VDD Value Register LSBs (Read-Only) [Address = 03h] External Temperature Value and AIN1 to AIN4 Register LSBs (Read-Only) [Address = 04h] AIN5 to AIN8 Registers LSBs (Read-Only) [Address = 05h] VDD Value Register MSBs (Read-Only) [Address = 06h] Internal Temperature Value Register MSBs (Read-Only) [Address = 07h] External Temperature Value or AIN1 Register MSBs (Read-Only) [Address = 08h] AIN2 Register MSBs (Read) [Address = 09h] AIN3 Register MSBs (Read) [Address = 0Ah] AIN4 Register MSBs (Read) [Address = 0Bh] AIN5 Register MSBs (Read) [Address = 0Ch] AIN6 Register MSBs (Read) [Address = 0Dh] AIN7 Register MSBs (Read) [Address = 0Eh] AIN8 Register MSBs (Read) [Address = 0Fh] Control Configuration 1 Register (Read/Write) [Address = 18h] Control Configuration 2 Register (Read/Write) [Address = 19h] Control Configuration 3 Register (Read/Write) [Address = 1Ah] Interrupt Mask 1 Register (Read/Write) [Address = 1Dh] Interrupt Mask 2 Register (Read/Write) [Address = 1Eh] Internal Temperature Offset Register (Read/Write) [Address = 1Fh] External Temperature Offset Register (Read/Write) [Address = 20h] VDD VHIGH Limit Register (Read/Write) [Address = 23h] VDD VLOW Limit Register (Read/Write) [Address = 24h] Internal THIGH Limit Register (Read/Write) [Address = 25h] Internal TLOW Limit Register (Read/Write) [Address = 26h] External THIGH/AIN1 VHIGH Limit Register (Read/Write) [Address = 27h] External TLOW/AIN1 VLOW Limit Register (Read/Write) [Address = 28h] AIN2 VHIGH Limit Register (Read/Write) [Address = 2Bh] AIN2 VLOW Limit Register (Read/Write) [Address = 2Ch] AIN3 VHIGH Limit Register (Read/Write) [Address = 2Dh] AIN3 VLOW Limit Register (Read/Write) [Address = 2Eh] AIN4 VHIGH Limit Register (Read/Write) [Address = 2Fh] AIN4 VLOW Limit Register (Read/Write) [Address = 30h] AIN5 VHIGH Limit Register (Read/Write) [Address = 31h] AIN5 VLOW Limit Register (Read/Write) [Address = 32h] AIN6 VHIGH Limit Register (Read/Write) [Address = 33h] AIN6 VLOW Limit Register (Read/Write) [Address = 34h] AIN7 VHIGH Limit Register (Read/Write) [Address = 35h] AIN7 VLOW Limit Register (Read/Write) [Address = 36h] AIN8 VHIGH Limit Register (Read/Write) [Address = 37h] AIN8 VLOW Limit Register (Read/Write) [Address = 38h] Device ID Register (Read-Only) [Address = 4Dh] Manufacturer’s ID Register (Read-Only) [Address = 4Eh] Silicon Revision Register (Read-Only) [Address = 4Fh] SPI Lock Status Register (Read-Only) [Address = 7Fh] Serial Interface Serial Interface Selection I2C Serial Interface Writing to the ADT7411 Writing to the Address Pointer Register for a Subsequent Read Writing Data to a Register Reading Data from the ADT7411 SPI Serial Interface Write Operation Read Operation SMBus/SPI INT/INTB SMBus Alert Response Outline Dimensions Ordering Guide