# Forward voltage tolerance on an ordinary diode

If one examines the datasheet of a diode such as the Vishay US1G, there is a graph of the typical voltage vs current such as Figure 3 below (with multiple lines for different temperatures):

However, there are very few guaranteed specifications for the forward voltage at any given temperature. Typically, there will be a single value for a single current at 25C:

Since the typical value from the graph is about 0.85-0.90V at 1A, it would imply a tolerance a tolerance of 10-15%.

So my questions are:

• Is a 15% variation in voltage (and other parameters) realistic?
• Would this tolerance this hold for each V-I temperature curve?
• Is 15% also applicable a low currents (e.g. 0.01A in this instance)?
• Are there any parameters that are likely to have tighter and/or looser tolerances?
• Is 15% a reasonable tolerance value to assume between different part numbers (for ordinary diodes) and manufacturers?

Background: I am attempting to calculate min/max voltage requirements for a circuit. A diode is used for reverse voltage protection and thus will affect the limit. Of course, I can choose a different reverse blocking scheme with less of a voltage drop, but that's not the purpose of this question.

• Normally In typical diode application, we don't care much about voltage forward drop across the diode. But if we want to use a diode as a temperature sensor we have to calibrate the circuit every time we change the diodes. – G36 Jan 1 '19 at 10:30