ST10F272M-4TR3 STMicroelectronics, ST10F272M-4TR3 Datasheet - Page 135

• Manufacturer Part Number: ST10F272M-4TR3
• Description: MCU 16BIT 256K FLASH 144-LQFP
• Manufacturer: STMicroelectronics
• Series: ST10r

Specifications of ST10F272M-4TR3

• 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

ST10F272M
24.7.4
Figure 39. A/D conversion characteristics
Analog reference pins
The accuracy of the A/D converter depends on how accurate is its analog reference: a noise
in the reference results in at least that much error in a conversion. A low pass filter on the
A/D converter reference source (supplied through pins V
in order to clean the signal, minimizing the noise. A simple capacitive bypassing may be
sufficient in most of the cases; in presence of high RF noise energy, inductors or ferrite
beads may be necessary.
In this architecture, V
circuitry of the A/D converter: there is an effective DC current requirement from the
reference voltage by the internal resistor string in the R-C DAC array and by the rest of the
analog circuitry.
An external resistance on V
reasons, series resistance are not advisable, and more in general any series devices in the
filter network should be designed to minimize the DC resistance.
Analog input pins
To improve the accuracy of the A/D converter, it is definitively necessary that analog input
pins have low AC impedance. Placing a capacitor with good high frequency characteristics
at the input pin of the device, can be effective: the capacitor should be as large as possible,
ideally infinite. This capacitor contributes to attenuating the noise present on the input pin.
Digital out
(HEX)
Offset error OFS
3FD
3FC
3FE
3FB
3FA
3FF
007
006
005
004
003
002
001
000
1
2
AREF
3
and V
Ideal characteristic
4
AREF
1 LSB (ideal)
V
AIN
5
AGND
(LSB
could introduce error under certain conditions: for this
(7)
6
(4)
IDEAL
(3)
pins represents also the power supply of the analog
7
(2)
(5)
)[LSB
IDEAL
1018
= V
(6)
AREF
/1024]
1020
(1)
(1) Example of an actual transfer curve
(2) The ideal transfer curve
(3) Differential nonlinearity error (DNL)
(4) Integral nonlinearity error (INL)
(5) Center of a step of the actual transfer curve
(6) Quantization error (1/2 LSB)
(7) Total unadjusted error (TUE)
AREF
Offset error OFS
and V
1022
Electrical characteristics
AGND
1024
Bisector characteristic
), is recommended
Gain error GE
135/176