How to read datasheets
The top of an electrical characteristics table states "Ta = 25 °C, VDD = 3.3 V unless otherwise noted." Which is a correct point to note when reading this table?
- AValues can change with temperature and supply voltage, so also check the values and graphs specified over the full temperature range
- BThis condition merely records the test equipment settings and need not be of particular concern in design
- CThe 25 °C values are the worst case, so values at other temperatures will be better than these
Show answer and explanation
Answer: A. Values can change with temperature and supply voltage, so also check the values and graphs specified over the full temperature range
Electrical characteristic values are meaningful only together with their test conditions, such as temperature, supply voltage and load. The conditions at the top apply to every parameter whose row does not state other conditions. Values can change greatly with conditions: leakage current increases at high temperature, and output drive capability decreases at low supply voltage, for example. Many datasheets show values guaranteed over the full temperature range, such as −40 to 85 °C, in a separate column or in bold, so read the rows that match the actual operating conditions.