AD1403/AD1403A

REV. A

–3–

Figure 4. Change in Output Voltage vs. Load Current

Figure 5. Quiescent Current vs. Temperature

Typical Performance Curves–

VOLTAGE VARIATION VS. TEMPERATURE AND LINE

Some confusion exists in the area of defining and specifying ref-

erence voltage error over temperature. Historically, references

are characterized using a maximum deviation per degree Centi-

grade; i.e., 10 ppm/

°C. However, because of the inconsistent

nonlinearities in Zener references (butterfly or “S” type charac-

teristics), most manufacturers use a maximum limit error band

approach to characterize their references. This technique mea-

sures the output voltage at 3 to 5 different temperatures and

guarantees that the output voltage deviation will fall within the

guaranteed error band at these discrete temperatures. This ap-

proach, of course, makes no mention or guarantee of perfor-

mance at any other temperature within the operating

temperature range of the device.

The consistent Voltage vs. Temperature performance of a typi-

cal AD1403 is shown in Figure 6. Note that the characteristic is

quasi-parabolic, not the possible “S” type characteristics of clas-

sical Zener references. This parabolic characteristic permits a

maximum output deviation specification over the device’s full

operating temperature range, rather than just at 3 to 5 discrete

temperatures.