Ezurio BISMS02BI-01, Руководство пользователя, Страница: 5 / 25

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3.3
Electrical Specifications
3.3.1 Absolute Maximum ratings
Absolute maximum ratings for supply voltage and voltages on digital and analogue pins of the Module are listed
below; exceeding these values will cause permanent damage.
Parameter Min Max Unit
Peak current of power supply 0 100 mA
Voltage at digital pins -0.3 3.3 V
Voltage at POWER pin 3.3 7 V
3.3.2 Recommended Operating Parameters
3.3.2.1 Power Supply
Signal Name Pin No I/O Voltage level Comments
Vcc 1 I 3.3V to 7.0V I
typ
= 30mA
GND 4, 20, 29
The module contains a power on reset circuit that ensures the module is reset at power on. The internal reset
circuit is triggered when the input voltage to the module drops below ~1.7V and is hence only suitable for
providing a power on reset signal. If the supply voltage to the module can drop below the minimum voltage level
in normal operation, then it is recommended that an external brownout circuit is provided to assert the module
reset and to ensure that the module is reset when the module supply voltage drops below 3.1V.
This will ensure that the module will return to an operational state when the supply voltage comes back within
specification. For example, if the module supply can drop to 2.7V and then be restored to 3.3V there is no
guarantee that the module will still be operational unless the reset signal has been asserted.
3.3.2.2 RS-232 Interface
Signal Name Pin No I/O Signal level Comments
UART_TX 26 O V
OL
max=0.2V
V
OH
min=2.8V
UART_RX 24 I V
IL
max=0.8V
V
IH
min=2.1V
V
IH
max=3.4V
UART_CTS 25 I V
IL
max=0.8V
V
IH
min=2.1V
V
IH
max=3.4V
UART_RTS 23 O V
OL
max=0.2V
V
OH
min=2.8V
UART_DSR 28 I V
IL
max=0.8V
V
IH
min=2.1V
V
IH
max=3.4V
UART_DTR 27 O V
OL
max=0.2V
V
OH
min=2.8V
Shared with GPIO_3
UART_RI 22 I or O O/P : V
OL
max=0.2V
V
OH
min=2.8V
I/P : V
IL
max=0.8V
V
IH
min=2.1V
Direction may be programmed.