ST10F272M-4QR3 STMicroelectronics, ST10F272M-4QR3 Datasheet - Page 138

• Manufacturer Part Number: ST10F272M-4QR3
• Description: MCU 16BIT 256K FLASH 144-PQFP
• Manufacturer: STMicroelectronics
• Series: ST10r

Specifications of ST10F272M-4QR3

• Core Processor: ST10
• Core Size: 16-Bit
• Speed: 40MHz
• Connectivity: ASC, CAN, EBI/EMI, I²C, SSC, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 111
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 20K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 24x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 144-MQFP, 144-PQFP
• Processor Series: ST10F27x
• Core: ST10
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

Electrical characteristics
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The two transients above are not influenced by the voltage source that, due to the presence
of the R
C
respect to the sampling time (T
Figure
Calling f
the anti-aliasing filter, f
least 2f
the conversion period (T
T
selected (fastest conversion rate at a specific channel): in conclusion it is evident that the
time constant of the filter R
charge level on C
the sampling switch is closed.
Figure 42. Anti-aliasing filter and conversion rate
S
S
, which is just a portion of it, even when fixed channel continuous conversion mode is
with respect to the ideal source V
A second charge transfer involves also C
capacitance) through the resistance R
and C
time constant is:
In this case, the time constant depends on the external circuit: in particular imposing
that the transient is completed well before the end of sampling time T
R
Of course, R
combination with R
definitively bigger than C
charge transfer transient) will be much higher than V
respected (charge balance assuming now C
L
42).
0
F
sizing is obtained:
0
; it means that the constant time of the filter is greater than or at least equal to twice
Anti-aliasing filter (f
C
Analog source bandwidth (V
the bandwidth of the source signal (and as a consequence the cut-off frequency of
F
S
filter, is not able to provide the extra charge to compensate the voltage drop on
were in parallel to C
V A2
S
L
f
f
must also be sized according to the current limitation constraints, in
0
cannot be modified by the analog signal source during the time in which
F
⋅
(
C S C P1 C P2 C F
F
F
= RC filter pole)
), according to Nyquist theorem the conversion rate f
S
C
10
Noise
+
). Again the conversion period T
(source impedance) and R
F
⋅
C
f
f
τ 2
A
P1
F
)
S
+
is definitively much higher than the sampling time T
, C
τ 2
=
). The filter is typically designed to act as anti-aliasing (see
P1
10
P2
<
(since the time constant in reality would be faster), the
R L
A
⋅
+
and C
; the time constant R
R
⋅
L
(
)
⋅
C S
L
=
S
: again considering the worst case in which C
(
V A C F
, then the final voltage V
C S
F
+
T
f
2 f
Sampled signal spectrum (f
F
(that is typically bigger than the on-chip
⋅
C P1
C
+
= f
0
S
≤ 2 R
≤ f
C P1
0
already charged at V
C
(Anti-aliasing filtering condition)
+
(Nyquist)
+
F
F
C
V A1
C P2
(filter resistance). Being C
F
+
f
(conversion rate vs. filter pole)
0
C P2
A1
C
⋅
)
F
. The following equation must be
(
is longer than the sampling time
C P1 C P2
C
) T S
F
≤
of the filter is very high with
+
C
= conversion rate)
A2
f
C
+
(at the end of the
A1
C S
S
):
, a constraint on
)
C
must be at
ST10F272M
F
f
S
, so the
P2