Datasheet
DocID027590 Rev 4 43/227
STM32F745xx STM32F746xx Functional overview
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2.38 General-purpose input/outputs (GPIOs)
Each of the GPIO pins can be configured by software as output (push-pull or open-drain,
with or without pull-up or pull-down), as input (floating, with or without pull-up or pull-down)
or as peripheral alternate function. Most of the GPIO pins are shared with digital or analog
alternate functions. All GPIOs are high-current-capable and have speed selection to better
manage internal noise, power consumption and electromagnetic emission.
The I/O configuration can be locked if needed by following a specific sequence in order to
avoid spurious writing to the I/Os registers.
Fast I/O handling allowing maximum I/O toggling up to 108 MHz.
2.39 Analog-to-digital converters (ADCs)
Three 12-bit analog-to-digital converters are embedded and each ADC shares up to 16
external channels, performing conversions in the single-shot or scan mode. In scan mode,
automatic conversion is performed on a selected group of analog inputs.
Additional logic functions embedded in the ADC interface allow:
• Simultaneous sample and hold
• Interleaved sample and hold
The ADC can be served by the DMA controller. An analog watchdog feature allows very
precise monitoring of the converted voltage of one, some or all selected channels. An
interrupt is generated when the converted voltage is outside the programmed thresholds.
To synchronize A/D conversion and timers, the ADCs could be triggered by any of TIM1,
TIM2, TIM3, TIM4, TIM5, or TIM8 timer.
2.40 Temperature sensor
The temperature sensor has to generate a voltage that varies linearly with temperature. The
conversion range is between 1.7 V and 3.6 V. The temperature sensor is internally
connected to the same input channel as V
BAT
, ADC1_IN18, which is used to convert the
sensor output voltage into a digital value. When the temperature sensor and V
BAT
conversion are enabled at the same time, only V
BAT
conversion is performed.
As the offset of the temperature sensor varies from chip to chip due to process variation, the
internal temperature sensor is mainly suitable for applications that detect temperature
changes instead of absolute temperatures. If an accurate temperature reading is needed,
then an external temperature sensor part should be used.
2.41 Digital-to-analog converter (DAC)
The two 12-bit buffered DAC channels can be used to convert two digital signals into two
analog voltage signal outputs.
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