71M6513H Maxim, 71M6513H Datasheet - Page 82

• Manufacturer Part Number: 71M6513H
• Description: The 71M6513 and 71M6513H are highly integrated SoCs with an MPU core, RTC, flash, and LCD driver
• Manufacturer: Maxim

For the 71M6513 (regular accuracy parts), the temperature coefficients TC1 and TC2 are given as constants that represent
typical component behavior (in µV/°C
PPM/°C.
For the high-accuracy parts, individualized coefficients TC1 and TC2 can be retrieved from the on-chip fuses via TRIMBGA,
TRIMBGB, TRIMM[2:0] (see Section ‘Distinction between 71M6513 and 71M6513H
allow compensation for variations of the reference voltage to within ±10 PPM/°C
Close examination of the electrical specification (see Table 62) for the 71M6513 reveals that the achievable deviation is not
strictly ±40 PPM/°C over the whole temperature range: Only for temperatures for which T-22 > 40 (i.e. T > 62°C) or for which
T-22 < -40 (i.e. T < -18°C), the data sheet states ±40 PPM/°C. For temperatures between -18°C and +62°C, the error should
be considered constant at ±1,600 PPM, or ±0.16%.
Similar considerations apply to the high-accuracy part 71M6513H (see Table 63), where the error around the calibration
temperature should be considered constant at ±600 PPM, or ±0.06%.
Page: 82 of 104
Figure 31 and Figure 32 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 ±630 PPM (or 0.063%) for the 71M6513H is reached at the temperature extremes. If the
reference voltage is used to measure both voltage and current, the identical errors of ±0.063% add up to a maximum Wh
registration error of ±0.126%.
Since TC1 and TC2 are given in µV/°C and µV/°C
taken into account when transitioning to PPM/°C and PPM/°C
PPMC2 = 1374*TC2/1.195).
A Maxim Integrated Products Brand
Parameter
VREF(T) deviation from VNOM(T)
Parameter
VREF(T) deviation from VNOM(T)
VREF
VREF
VNOM
VNOM
(
(
T
T
Table 62: VREF Definition for the Regular Accuracy Parts 71M6513
)
)
−
−
Table 63: VREF Definition for the High-Accuracy Parts 71M6513H
VNOM
VNOM
(
(
T
T
)
)
2
). TC1 and TC2 allow compensation for variations of the reference voltage to within ±40
(
(
T
T
)
)
© 2005-2011 Teridian Semiconductor Corporation
max(
max(
Temperature Compensation
T
T
10
10
−
−
6
6
22
22
,
,
40
40
2
, respectively, the value of the VREF voltage (1.195V) has to be
)
)
Min
Min
3-Phase Energy Meter IC
-40
-10
2
. This means that PPMC = 26.84*TC1/1.195 and
71M6513/71M6513H
Parts’).
DATA SHEET
+40
+10
For the 71M6513H, TC1 and TC2
Typ
Typ
PPM/ºC
PPM/ºC
AUGUST 2011