ST X-NUCLEO-SRC1M1, Руководство пользователя, Страница: 11 / 26

Figure 13. TCPP02-M18
3. 3 V
High input voltage
85 mA LDO linear regulator
GND GND
3.3V
NRST
U2 ST715PU33R
IN
1
9
Exp Pad GND
OUT
8
NC1
2
NC2
3
GND
4
NC3
7
NC4
6
FB
5
JP1
TSW-102-07-F-D
1 2
3 4
R23
1k
D8
LED green
C6
470n 5V
1
2
C5
100n 25V
1
2
Provider
GND
SOURCE
R22
4k
D7
LED5 blue
1.3 STM32 resources
The STM32 resources provided to the TCPP02-M18 are compliant with 1.8 V and 3.3 V. This allows using the 1.8
V of the STM32 with a minor change: decrease the voltage divider resistors (R4 and R9) to 20 k in order to set the
divider ratio to 11.
To start a USB Power Delivery source, the required resources on the STM32 are:
•
the UCPD peripheral that manages the USB Power Delivery protocol;
• the I2C bus that can be shared with other slaves;
• the ADC to get the V
BUS
voltage image.
To optimize the power consumption on the battery-powered system, at cable attach, you have to switch the
TCPP02-M18 from the low-power mode to the normal mode with the I2C request, to ensure a good USB-PD
communication through the CC lines.
Optional resources are:
•
a USB 2.0 peripheral;
• an ADC to get the provider path voltage and the current on the V
BUS
images.
Table 2. STM32 resources coming from the X-NUCLEO-SRC1M1
What USB-PD minimal resources Additional features Comments
UCPD CC1 X USB-PD CC
UCPD CC2 X USB-PD CC
I2C SCL X I2C bus clock
I2C SDA X I2C bus data
GPIO FlLGN X Fault flag
ADC VBUSc X
V
BUS
voltage info
ADC provider X Provider path voltage info
ADC Isense X
Current on V
BUS
for PPS
GPIO ENABLE X
V
DD
via GPIO
USB D+ X USB 2.0 data line
USB D- X USB 2.0 data line
UM2973
STM32 resources
UM2973 - Rev 1
page 11/25