71M6533 Datasheet, PDF (71/132 Pages) Teridian Semiconductor Corporation – Energy Meter IC

FDS_6533_6534_004
71M6533/G/H and 71M6534/H Data Sheet
Error Band (PPM) over Temperature (°C)
2800
2400
2000
1600
1200
800
400
0
-400
-800
-1200
-1600
-2000
-2400
-2800
±40 PPM/°C
±40 PPM/°C
-40
-20
0
20
40
60
80
Figure 34: Error Band for VREF over Temperature (Regular-Accuracy Parts)
Error Band (PPM) over Temperature (°C)
1200
±15 PPM/°C
800
400
0
-400
-800
-1200
±15 PPM/°C
-40
-20
0
20
40
60
80
Figure 35: Error Band for VREF over Temperature (High-Accuracy Parts)
4.1.1 Temperature Compensation for VREF
The bandgap temperature is used to digitally compensate the power outputs for the temperature dependence
of VREF, using the CE register GAIN_ADJ (internal temperature compensation). Since the band gap amplifier
is chopper-stabilized via the CHOP_E[1:0] field, the most significant long-term drift mechanism in the voltage
reference is removed.
In internal temperature compensation mode, the CE applies the following formula to determine the GAIN_ADJ
value. In this formula TEMP_X is the deviation from nominal or calibration temperature expressed in multiples
of 0.1 °C:
GAIN
_
ADJ
= 16385 +
TEMP
_X⋅
2¹⁴
PPMC
+
TEMP
_
X²â‹…
2²³
PPMC 2
Rev 2
71