MC56F8346 Freescale Semiconductor, Inc, MC56F8346 Datasheet - Page 163

• Manufacturer Part Number: MC56F8346
• Description: 56f8300 16-bit Digital Signal Controllers
• Manufacturer: Freescale Semiconductor, Inc

Equivalent Circuit for ADC Inputs
Figure 10-22 ADC Absolute Error Over Processing and Temperature Extremes Before
and After Calibration for VDC
= 0.60V and 2.70V
in
Note: The absolute error data shown in the graphs above reflects the effects of both gain error and offset
error. The data was taken on 15 parts: three each from four processing corner lots as well as three from one
nominally processed lot, each at three temperatures: -40°C, 27°C, and 150°C (giving the 45 data points
shown above), for two input DC voltages: 0.60V and 2.70V. The data indicates that for the given
population of parts, calibration significantly reduced (by as much as 39%) the collective variation (spread)
of the absolute error of the population. It also significantly reduced (by as much as 80%) the mean
(average) of the absolute error and thereby brought it significantly closer to the ideal value of zero.
Although not guaranteed, it is believed that calibration will produce results similar to those shown above
for any population of parts including those which represent processing and temperature extremes.
10.17 Equivalent Circuit for ADC Inputs
Figure 10-23
illustrates the ADC input circuit during sample and hold. S1 and S2 are always open/closed
56F8346 Technical Data, Rev. 15
Freescale Semiconductor
163
Preliminary