c8051f410 Silicon Laboratories, c8051f410 Datasheet - Page 58

• Manufacturer Part Number: c8051f410
• Description: 2.0 V, 32/16 Kb Flash, Smartclock, 12-bit Adc
• Manufacturer: Silicon Laboratories

C8051F410/1/2/3
5.3.6. Settling Time Requirements
A minimum tracking time is required before an accurate conversion can be performed. This tracking time is
determined by the AMUX0 resistance, the ADC0 sampling capacitance, any external source resistance,
and the accuracy required for the conversion.
Figure 5.6 shows the equivalent ADC0 input circuit. The required ADC0 settling time for a given settling
accuracy (SA) may be approximated by Equation 5.1. When measuring the Temperature Sensor output or
V
tling time requirements.
Where:
SA is the settling accuracy, given as a fraction of an LSB (for example, 0.25 to settle within 1/4 LSB)
t is the required settling time in seconds
R
n is the ADC resolution in bits (12).
58
DD
TOTAL
with respect to GND, R
is the sum of the AMUX0 resistance and any external source resistance.
Equation 5.1. ADC0 Settling Time Requirements
Figure 5.6. ADC0 Equivalent Input Circuits
TOTAL
Px.x
t
reduces to R
=
ln
RC
⎛
⎝
MUX Select
Input
------ -
SA
2
n
= R
⎞
⎠
×
MUX
MUX
Rev. 1.0
R
R
* C
TOTAL
. See Table 5.3 and Table 5.4 for ADC0 minimum set-
MUX
SAMPLE
= 5
C
kΩ
SAMPLE
C
SAMPLE
= 12 pF