Datasheet

71M6521DE/DH/FE Data Sheet
Page: 62 of 107 Rev 3
Parameter
Condition
Min
Typ
VREF(T) deviation from VNOM(T)
)40,22max(
10
)(
)()(
6
−
−
TTVNOM
TVNOMTVREF
-20 +20 PPM/ºC
Table 62: VREF Definition for the High-Accuracy Parts
Figure 30 and Figure 31 show this concept graphically. The “box” from -18°C to +62°C reflects the fact that it is
impractical to measure the temperature coefficient of high-quality references at small temperature excursions. For
example, at +25°C, the expected error would be ±3°C * 40 PPM/°C, or just 0.012% for the regular-accuracy parts..
The maximum deviation of ±2520 PPM (or 0.252%) for the regular-accuracy parts is reached at the temperature
extremes. If the reference voltage is used to measure both voltage and current, the identical errors of ±0.252% add
up to a maximum Wh registration error of ±0.504%.
The maximum deviation of ±1260 PPM (or 0.126%) for the high-accuracy parts is reached at the temperature
extremes. If the reference voltage is used to measure both voltage and current, the identical errors of ±0.126% add
up to a maximum Wh registration error of ±0.252%.
Figure 30: Error Band for VREF over Temperature (Regular-Accuracy Parts)
-2800
-2400
-2000
-1600
-1200
-800
-400
0
400
800
1200
1600
2000
2400
2800
-40 -20 0 20 40 60 80
Error Band (PPM) over Temperature (°C)
±40 PPM/°C
±40 PPM/°C