Datasheet

t >
sample
(R + R ) × ln(2 ) × C
S I I
11
t
REFBURST
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For example, if R
S
is 10 kΩ, t
sample
must be greater than 2.47 µs.
When the reference buffer is used in burst mode, the sampling time must be greater than the sampling
time calculated and the settling time of the buffer, t
REFBURST
:
For example, if V
Ref
is 1.5 V and R
S
is 10 kΩ, t
sample
must be greater than 2.47 µs when ADC10SR = 0, or
2.5 µs when ADC10SR = 1. See the device-specific data sheet for parameters.
To calculate the buffer settling time when using an external reference, the formula is:
t
REFBURST
= S
R
× V
Ref
− 0.5 µs
Where:
SR = Buffer slew rate (~1 µs/V when ADC10SR = 0 and ~2 µs/V when ADC10SR = 1)
V
Ref
= External reference voltage
22.2.6 Conversion Modes
The ADC10 has four operating modes selected by the CONSEQx bits as discussed in Table 22-1.
Table 22-1. Conversion Mode Summary
CONSEQx Mode Operation
00 Single channel single-conversion A single channel is converted once.
01 Sequence-of-channels A sequence of channels is converted once.
10 Repeat single channel A single channel is converted repeatedly.
11 Repeat sequence-of-channels A sequence of channels is converted repeatedly.
539
SLAU144J–December 2004–Revised July 2013 ADC10
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