ST10F273Z4 STMicroelectronics, ST10F273Z4 Datasheet - Page 144

• Manufacturer Part Number: ST10F273Z4
• Description: 16-BIT MICROCONTROLLER WITH MAC UNIT, UP TO 832 KBYTES FLASH MEMORY AND UP TO 68 KBYTES RAM
• Manufacturer: STMicroelectronics

Specifications of ST10F273Z4

• Single Voltage Supply: 5 V ±10%

Electrical characteristics
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2.
3.
4.
5.
For complete set of parameters characterizing the ST10F273Z4 A/D Converter equivalent
circuit, refer to
Supposing to design the filter with the pole exactly at the maximum frequency of the
signal, the time constant of the filter is:
Using the relation between C
it is possible to define C
As a consequence of step 1 and 2, RC can be chosen:
Considering the current injection limitation and supposing that the source can go up to
12V, the total series resistance can be defined as:
from which is now simple to define the value of R
Now the three element of the external circuit R
conditions discussed in the previous paragraphs have been used to size the
component, the other must now be verified. The relation which allow to minimize the
accuracy error introduced by the switched capacitance equivalent resistance is in this
case:
So the error due to the voltage partitioning between the real resistive path and C
less then half a count (considering the worst case when V
The other conditions to be verified is the time constants of the transients are really and
significantly shorter than the sampling period duration T
Section 24.7: A/D converter characteristics on page
τ 1
10 τ 2
=
V A
(
⋅
R SW
⋅
=
R S R F R L R SW R AD
-------------------------------------------------------------------------- -
10 R ⋅ L
F
+
+
:
R AD
R L
R S
R F
⋅
(
F
+
C S
=
R C C F
and C
=
C F
+
R EQ
)
R EQ
V AM
------------ - R F R S
⋅
I INJ
+
-------------------- -
2πf 0 C F
R F
C S
+
=
C P1
=
1
4000 C S
=
=
+
S
–
-------------- -
f C C S
and taking some margin (4000 instead of 2048),
R L
2.8ns
----------- -
2πf 0
+
1
1
=
+
C P2
⋅
=
–
995Ω
=
=
V AM
------------ -
I INJ
=
)
15.9µs
10MΩ
=
16nF
T
F
=
=
, C
S
290ns
=
≅
2.35mV
2.9kΩ
L
= 1µs
:
1kΩ
F
4kΩ
and R
S
<
:
A
L
1
-- - LSB
2
T
= 5V):
are defined. Some
S
= 1µs
135.
ST10F273Z4
S
is