STR731FV1T6 STMicroelectronics, STR731FV1T6 Datasheet - Page 45

• Manufacturer Part Number: STR731FV1T6
• Description: MCU 32BIT 128K FLASH 100-TQFP
• Manufacturer: STMicroelectronics
• Series: STR7r

Specifications of STR731FV1T6

• Core Processor: ARM7
• Core Size: 32-Bit
• Speed: 36MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 72
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP, 100-VQFP
• Processor Series: STR731x
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: CAN, I2C, SPI, UART
• Maximum Clock Frequency: 36 MHz
• Number Of Programmable I/os: 72
• Number Of Timers: 9
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWARM, EWARM-BL, MCBSTR730, KSK-STR731-PL, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: STR730-SK/HIT, STR730-SK/RAIS, STR731-SK/IAR, STR730-EVAL, STX-PRO/RAIS, STX-RLINK, STR79-RVDK/CPP, STR79-RVDK, STR79-RVDK/UPG
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

STR73xFxx
Analog power supply and reference pins
The V
the high and low reference voltages for the conversion.
Separation of the digital and analog power pins allow board designers to improve A/D
performance. Conversion accuracy can be impacted by voltage drops and noise in the event
of heavily loaded or badly decoupled power supply lines
guidelines).
General PCB design guidelines
To obtain best results, some general design and layout rules should be followed when
designing the application PCB to shield the noise-sensitive, analog physical interface from
noise-generating CMOS logic signals.
●
●
●
●
Software filtering of spurious conversion results
For EMC performance reasons, it is recommended to filter A/D conversion outliers using
software filtering techniques.
Figure 23. Power supply filtering
Use separate digital and analog planes. The analog ground plane should be connected
to the digital ground plane via a single point on the PCB.
Filter power to the analog power planes. It is recommended to connect capacitors, with
good high frequency characteristics, between the power and ground lines, placing
0.1 µF and optionally, if needed 10 pF capacitors as close as possible to the STR7
power supply pins and a 1 to 10 µF capacitor close to the power source (see
Figure
The analog and digital power supplies should be connected in a star network. Do not
use a resistor, as V
resistance would cause a voltage drop and a loss of accuracy.
Properly place components and route the signal traces on the PCB to shield the analog
inputs. Analog signals paths should run over the analog ground plane and be as short
as possible. Isolate analog signals from digital signals that may switch while the analog
inputs are being sampled by the A/D converter. Do not toggle digital outputs near the
A/D input being converted.
DDA
and V
23).
SSA
pins are the analog power supply of the A/D converter cell. They act as
DDA
is used as a reference voltage by the A/D converter and any
POWER
SUPPLY
SOURCE
5V
1 to 10 μF
STR7
DIGITAL NOISE
FILTERING
EXTERNAL
NOISE
FILTERING
(see: General PCB design
0.1 μF
0.1 μF
V
V
V
V
SS
DD
DDA
SSA
Electrical parameters
STR73x
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