STMicroelectronics B-G474E-DPOW1 User manual

Introduction
The B-G474E-DPOW1 Discovery kit is a digital power solution and a complete demonstration and development platform for the
STMicroelectronics Arm® Cortex®-M4 core-based STM32G474RET6 microcontroller. Leveraging the new HRTimer-oriented
features, 96 Kbytes of embedded RAM, math accelerator functions, and USB PD3.0 offered by STM32G474RET6, the B-
G474E-DPOW1 Discovery kit helps the user to prototype applications with digital power such as a buck-boost converter, RGB
power LED lighting, or a class-D audio amplifier, based on the USB Type-C® 2.0 FS connector interface. The B-G474E-DPOW1
Discovery kit does not require any separate probe as it integrates the STLINK-V3E debugger and programmer.
The STM32G474RET6 microcontroller features FMAC and CORDIC mathematical hardware accelerator, five 12-bits ADCs
(5 MSPS) up to 42 channels and with resolution up to 16-bit with hardware oversampling, seven 12-bit DAC channels, seven
ultra-fast rail-to-rail analog comparators, six operational amplifiers with PGA mode, seventeen timers with various advanced
functionalities, four I2C fast-mode plus, five USARTs, one LPUART, four SPIs, one SAI, three CAN‑FD controllers, one USB 2.0
full-speed interface and a UCPD block allowing connection to USB Type-C® compatible with USB Power Delivery, a true
random number generator, one FMC parallel synchronous interface, a quad-SPI memory interface, SWD and JTAG debugging
support.
This Discovery kit offers everything required for users to start and develop applications. The hardware features on the board
help to evaluate the following peripherals: USB Type-C® compatible with USB PD3.0, HRTimer evaluation, digital power for
buck-boost application with Class-D audio amplifier and RGB power LED lighting. Thanks to its two 32-pin 2.54 mm pitch
extension connectors, it also enables users to plug it on a breadboard for prototyping. The integrated STLINK-V3E provides an
embedded in-circuit debugger and programmer for the STM32 MCU.
The B-G474E-DPOW1 Discovery kit comes with the STM32 comprehensive free software libraries and examples available with
the STM32Cube package.
Figure 1. B-G474E-DPOW1 top view Figure 2. B-G474E-DPOW1 bottom view
Pictures are not contractual.
Discovery kit with STM32G474RE MCU
UM2577
User manual
UM2577 - Rev 2 - September 2020
For further information contact your local STMicroelectronics sales office. www.st.com

1Features
• STM32G474RET6 Arm® Cortex®-M4 core-based microcontroller, featuring 512 Kbytes of Flash memory and
128 Kbytes of SRAM, in LQFP64 package
• USB Type-C® with USB 2.0 FS interface compatible with USB-PD 3.0
• RGB power LED for a bright lighting
• Digital power buck-boost converter with internal or external Input voltage and with onboard resistor loads
• Audio Class-D amplifier capable
• 4 user LEDs
• 3 LEDs for power and ST-LINK communication
• 4-direction joystick with a selection button
• Reset push-button
• Board connectors:
–USB Type-C®
– USB Micro-B
– 2 x 32-pin header, 2.54 mm pitch, daughterboard extension connector for breadboard connection
•Flexible power-supply options: ST-LINK USB VBUS or USB Type-C® VBUS or external source
• On-board STLINK-V3E debugger/programmer with USB re-enumeration capability: mass storage, Virtual
COM port, and debug port
• Comprehensive free software libraries and examples available with the STM32CubeG4 MCU Package
• Support of a wide choice of Integrated Development Environments (IDEs) including IAR Embedded
Workbench®, MDK-ARM, and STM32CubeIDE
• Handled by STM32CubeMonitor-UCPD (STM32CubeMonUCPD) software tool
Note: Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.
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Features
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2Ordering information
To order the B-G474E-DPOW1 Discovery kit, refer to Table 1. Additional information is available from the
datasheet and reference manual of the target STM32.
Table 1. Ordering information
Order code Board reference Target STM32
B-G474E-DPOW1 MB1428 STM32G474RET6U
2.1 Product marking
Evaluation tools marked as “ES” or “E” are not yet qualified and therefore not ready to be used as reference
design or in production. Any consequences deriving from such usage will not be at ST charge. In no event, ST will
be liable for any customer usage of these engineering sample tools as reference designs or in production.
“E” or “ES” marking examples of location:
• On the targeted STM32 that is soldered on the board (For an illustration of STM32 marking, refer to the
STM32 datasheet “Package information” paragraph at the www.st.com website).
• Next to the evaluation tool ordering part number that is stuck or silk-screen printed on the board.
This board features a specific STM32 device version, which allows the operation of any bundled commercial
stack/library available. This STM32 device shows a "U" marking option at the end of the standard part number
and is not available for sales.
In order to use the same commercial stack in his application, a developer may need to purchase a part number
specific to this stack/library. The price of those part numbers includes the stack/library royalties.
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Ordering information
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3Development environment
3.1 System requirements
• Windows® OS (7, 8, and 10), Linux® 64-bit, or macOS®
• USB Type-A or USB Type-C® to Micro-B cable (not included)
• USB Type-C® to USB Type-C® cable (included)
Note: macOS® is a trademark of Apple Inc. registered in the U.S. and other countries.
All other trademarks are the property of their respective owners.
3.2 Development toolchains
• IAR Systems - IAR Embedded Workbench®(1)
• Keil® - MDK-ARM(1)
• STMicroelectronics - STM32CubeIDE
1. On Windows® only.
3.3 Demonstration software
The demonstration software, included in the STM32Cube MCU Package corresponding to the on-board
microcontroller, is preloaded in the STM32 Flash memory for easy demonstration of the device peripherals in
standalone mode. The latest versions of the demonstration source code and associated documentation can be
downloaded from www.st.com.
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Development environment
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4Technology partners
• Wurth Electronics:
– Current sense transformer, 1:125 ratio, 6 to 6.5 mΩ, 3 mH, 10 A, part number 749251125
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Technology partners
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5Conventions
Table 2 provides the conventions used for the ON and OFF settings in the present document.
Table 2. ON/OFF convention
Convention Definition
Jumper JPx ON Jumper fitted
Jumper JPx OFF Jumper not fitted
Jumper JPx [1-2] Jumper fitted between Pin 1 and Pin 2
Solder bridge SBx ON SBx connections closed by 0 Ω resistor
Solder bridge SBx OFF SBx connections left open
Resistor Rx ON Resistor soldered
Resistor Rx OFF Resistor not soldered
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Conventions
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6Limitations
6.1 USB Type-C® VBUS limitation
By default, only a USB Type-C® VBUS nominal voltage of 5 V must be used. For any other VBUS nominal voltage,
refer to the technical application note and specific configuration.
6.2 Debug connector configuration
According to the board revision, an STDC14 or a MIPI10 connector is soldered onto the CN1 STDC14 footprint.
Refer to Section 14.2 CN1 debug connector.
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Limitations
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7Quick start
This section describes how to start development quickly using the STM32 Discovery board.
Before installing and using the product, accept the Evaluation Product License Agreement from the www.st.com/
epla webpage.
The Discovery board is a low-cost and easy-to-use development kit to quickly evaluate and start development
with an STM32 microcontroller in QFP64 package. To start using this board, follow the steps below:
1. For correct identification of all device interfaces from the host PC, install the Discovery USB driver available
on the B-G474E-DPOW1 webpage, prior to connecting the board.
2. Check that jumpers JP4 and JP7 are ON, JP5 is set on STLK, JP6 is OFF, SW1 octal switch is set to ALL
ON (Low physical position), and JP1 is set on VIN - USBPD pins.
3. Connect a Type-A to Micro-B USB cable (not included) from the STM32G474 Discovery board (CN3) to a
PC to power the board. The LEDs LD6 (3V3), LD7 (5V), and LD9 (COM) light up.
4. User LEDs LD2, LD3, LD4, and LD5 scroll, indicating the demonstration application software startup.
5. The demo application software and its user manual, as well as other software examples for exploring
STM32G4 features are available at B-G474E-DPOW1.
6. Develop an application using the available examples.
STLINK-V3E firmware upgrade
The STLINK-V3E embeds a firmware upgrade mechanism for an in-situ upgrade through the USB port. As the
firmware may evolve during the lifetime of the STLINK-V3E product, with new functionalities, bug fixes, support
for new microcontroller families, it is recommended to visit the www.st.com website, before starting to use the B-
G474E-DPOW1 Discovery kit and periodically, to stay up-to-date with the latest firmware version.
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Quick start
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8Hardware layout and configuration
The B-G474E-DPOW1 Discovery kit is designed around the STM32G474RET6 microcontroller, in 64-pin LQFP
package. The hardware block diagram (Refer to Figure 3) illustrates the connection between the microcontroller
and the peripherals (RGB power LED and buck LED, digital power buck-boost, LTC3114 5 V converter,
embedded ST-LINK/V3E, USB Type-C® 2.0 FS, 4 user LEDs and a joystick as user interface, 2 x 32 pin extension
connector headers). Figure 4 and Figure 5 help to locate these features on the B-G474E-DPOW1 board.
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Hardware layout and configuration
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Figure 3. Hardware layout and configuration
RGB power LED
+
3 buck LEDs
Double
switch
VIN
connector
UCPD NRST
LTC3114
5 V converter
I/Os
RC Sinus
TAG connector
DIGITAL POWER
BUCK-BOOST
SWD /
USART_VCP
STM32G474RET6U
3.3V power
Octal
mechanical
switch
Embedded
STLINK-V3E
Micro-USB
DEBUG
connector
RESET
button
USB 2.0 FS
Type-C®
receptacle
I/Os
32-pin
extension
connector
headers
32-pin
extension
connector
headers
HRTIMERs /
COMPs
HRTIMERs /
COMPs / ADCs
HRTIMER
Joystick
4-direction
+ Center key
I/Os
I/Os
I/OsI/O
VOUT
connector
VOUT
loads
USBPD
detach ADC I/Os User LEDs
Speaker
option
HSE
oscillator
VREF
POWER
VBUS
VBUS
VBUS
VBUS
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Hardware layout and configuration
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8.1 Product layout (top and bottom)
Figure 4. B-G474E-DPOW1 top layout view
U3
STM32G474RET6U
U6 LTC3114-1
CN2
USB Type-C®
receptacle
CN3
USB micro-B
ST-LINK receptacle
U9 STLINK-V3E MCU
SW1
Octal mechanical
switch
JP7 TNRST
JP6 STLK NRST
CN1 DEBUG connector
JP5
5V_SELECTION
JP4 IDD
measurement
LD2, LD3, LD4, LD5
user LEDs
LD1
RGB power LED
B2
Joystick B1
RESET button
CN7
Buck-boost VOUT
JP2/JP3
Speaker connection
JP1 Buck-boost VIN
LD6
3V3 LED
LD7 5V LED
LD8 overcurrent LED
LD9 COM LED
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Product layout (top and bottom)
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Figure 5. B-G474E-DPOW1 bottom layout view
CN8
32-pin extension
connector
CN11
Corner jumper
CN12
Corner jumper
CN10
TAG connector
CN9
32-pin extension
connector
CN7
VOUT extension
connector
CN6
Corner jumper
CN11
Corner jumper
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Product layout (top and bottom)
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8.2 Mechanical drawing
Figure 6. B-G474E-DPOW1 mechanical drawing
55.88 mm
152.4 mm
1.5 mm
54.61 mm
6.35 mm
6.35 mm
7.62 mm
6.35 mm
6.35 mm
6.35 mm
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Mechanical drawing
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9Embedded STLINK-V3E
The new STLINK-V3E is the embedded version of the STLINK-V3 included in the design of the Discovery board.
It allows access to the Program/Debug and Monitoring functions of the STM32 through the USB STLK CN3
connector.
In order to use the entire STLINK-V3E programming, debugging, and monitoring functions through the CN3 USB
STLK connector, ensure the following configuration is set on the STM32 target (Refer to Figure 7):
• The SW1 octal mechanical switch must be set to ‘ALL ON’ configuration: all the 1.27 mm pitch switches
must be in a low physical position.
• The JP7 header must be equipped with a 2.54 mm jumper to connect the output reset from STLINK-V3E to
the TNRST reset input of the STM32G474RET6.
• The JP6 header must be OFF to set STLINK-V3E in Active mode.
• The JP4 header must be ON to power the STM32.
• The JP5 header must be ON (Power source selected and relevant power input connected as described in
Section 10.2 ).
• The CN1 debug and CN10 TAG connectors are not used.
Figure 7. Configuration to use STLINK-V3E
CN3
USB micro-B
ST-LINK receptacle
SW1
Octal mechanical
switch
JP7
TNRST
JP6
STLK NRST
CN1 debug
connector
JP5
5V_SELECTION
JP4
IDD
measurement
The B-G474E-DPOW1 product can be powered from the CN3 ST-LINK USB connector (STLK), but the host PC
only provides 100 mA to the ST-LINK circuit until the end of USB enumeration. Then, the B-G474E-DPOW1
product asks for the 500 mA power to the host PC.
If the host PC can provide the required power, the enumeration finishes by a SetConfiguration command, and
then, the power switch STMPS2151STR is turned ON, after which the B-G474E-DPOW1 product can draw a
current of 500 mA. At this step, the PC can rely on the STMPS2151STR overcurrent protection at 700 mA. In the
case of overcurrent detection, the FAULT pin is asserted which lights on the LD8 red LED (OC).
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Embedded STLINK-V3E
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If the host PC is not able to provide the requested current, the enumeration fails. Therefore, the STMPS2151STR
remains OFF and the 5 V power reference of the board is OFF. The 5 V Green LED LD7 is turned OFF.
The Green LED LD7 is turned ON when the B-G474E-DPOW1 product is powered by the 5V correctly. The COM
LED LD9 indicates the STLINK-V3E communication status with the host, refer to Overview of ST-LINK derivatives
technical note (TN1235).
Note:
In case the board is powered by a USB wall charger on CN3 with JP5 on STLK, there is no USB enumeration, so
the COM LED LD9 remains OFF, but the power switch is activated and the board is powered up, with 700 mA
current protection.
9.1 STLINK-V3E deactivation (Reset mode)
It is simple to deactivate the STLINK-V3E function, by adding a jumper on JP6 to connect STLK NRST to
GND, as shown in Figure 8 and Table 3. Programming, debugging, and monitoring through ST-LINK are
impossible in this Reset state, where all STLINK-V3E PIOs are in high impedance.
The Reset state is useful to connect external probe onto CN1 debug or CN10 TAG connectors for embedded
STM32 debug.
In this Reset state, if JP7 is OFF, 5V selection JP5 CHGR source can be used to power the board with no current
protection, but 5V selection JP5 STLK is not functional.
Figure 8. JP6 STLK NRST default configuration
Table 3. JP6 STLK NRST configuration
Reference Jumper(1) Function Comment
JP6(2) OFF STLINK-V3E active STLINK-V3E detects USBSTLK plug on CN3
ON STLINK-V3E Reset state Set STLINK-V3E in Reset mode (All IOs in high impedance)
1. The default setting is in bold.
2. In case JP6 is ON, JP7 must be OFF.
9.2 STLINK-V3E physical disconnection
It is possible to physically isolate partially or completely the STLINK-V3E signals from the rest of the
STM32 board by disconnecting part of physical signals or all of them:
• By default, STLINK-V3E is physically connected to STM32: SW1 is in ‘ALL ON’ low physical position, and
JP7 is ON, to enable the use of STLINK-V3E in Program/Debug/Monitoring modes. Refer to Figure 9,
Table 4, and Table 5 for a detailed description.
• In case of complete physical isolation, Octal Mechanical switch SW1 must be set in ‘ALL OFF’ and JP7 must
be OFF. The CN3 STLINK-V3E connector behaves like an external power supply with 5V selection coming
from either CHGR or STLK source. Program/Debug/Monitoring through ST-LINK are not possible.
• In case of partial signal connection is chosen, ensure the ST-LINK firmware and STM32 Target Software are
compatible with your selected SW1 / JP7 configuration.
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STLINK-V3E deactivation (Reset mode)
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Figure 9. SW1 and JP7 TNRST default configurations
Table 4. SW1 configuration
Pin number Function STLINK-V3E description State(1) Comment
1 PWREXT T_PWR_EXT (PB1) ON or OFF Connect or isolate STLINK-V3E from
general 5V power presence indicator
2 VCCAIN T_VCC_AIN (PA0) ON or OFF Connect or isolate STLINK-V3E from
general 3V3 power presence indicator
3 GNDDET GND detection (PG5) ON or OFF Connect or isolate STLINK-V3E from
debug connector
4 TVCP_ RX STLK_VCP_TX (PG14) ON or OFF Connect or isolate STLINK-V3E from
STM32
5 TVCP_TX STLK_VCP_RX (PG9) ON or OFF Connect or isolate STLINK-V3E from
STM32
6 TSWO T_SWO (PD2) ON or OFF Connect or isolate STLINK-V3E from
STM32
7 TSWCLK T_SWCLK (PH6) ON or OFF Connect or isolate STLINK-V3E from
STM32
8 TSWIO T_SWDIO_IN (PH7) /
T_SWDIO_OUT (PF9) ON or OFF Connect or isolate STLINK-V3E from STM32
1. ON (Default setting) means the switch is in Low physical position (L marking onboard), OFF means the switch is in High
physical position (H marking onboard)
Table 5. JP7 TNRST configuration
Reference Jumper(1) Function Comment
JP7 TNRST(2) ON T_NRST (PA6) STLINK-V3E output reset connected to T_NRST of STM32
OFF STLINK-V3E output reset isolated from T_NRST of STM32
1. The default setting is in bold.
2. In case JP7 is ON, JP6 must be OFF.
In case USB Type-C® connector is used to power the board (JP5 USBC setting), it is also possible to disconnect
the STLINK-V3E power, unsoldering the SB31 solder bridge. In that case, ensure all signals are previously
disconnected (SW1 in ALL OFF position, and JP7 OFF).
9.3 STLINK-V3E drivers
Before connecting the Discovery board to a Windows PC via USB, a driver for the STLINK-V3E must be installed.
It is available on the www.st.com website.
In case the Discovery board is connected to the PC before the driver is installed, some Discovery board interfaces
may be declared as “unknown” in the PC device manager. In this case, the user must install the driver files, and
update the driver of the connected device from the device manager (See Figure 10).
Note: Prefer using the “USB Composite Device” handle for a full recovery.
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STLINK-V3E drivers
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Figure 10. USB composite device
9.4 STLINK-V3E VCP configuration
STLINK-V3E supports Virtual COM port (VCP) by default. To disable this function, the relevant SW1 switches
linked to the VCP function can be set to the OFF state (See Table 4. SW1 configuration).
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STLINK-V3E VCP configuration
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10 Power supply
10.1 Power diagram
The following diagram describes the power architecture and the maximum voltage and current limits, under which
functions can be safely used on the B-G474E-DPOW1 product. In any case, ensure the total power budget of the
application always conforms to the selected 5V power source mode, if not malfunction can occur. For detailed
configuration, refer to the relevant function description and technical application notes.
Note: When using 5V_VOUT and 3V3_OUT to power external functions on 32-pin extension connectors, it can
be necessary to use one of the two following power sources, depending on the application power
budget:
•5V_USB_CHGR, up to 1.5 A
•5V_VIN, up to 1.5 A
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Power supply
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Figure 11. Power diagram
USB
Type-C®
USB
STLINK
3
2
p
i
n
E
X
T
3
2
p
i
n
E
X
T
LTC3114
5V Converter
BUCKBOOST
STMPS2151
USBPD_VBUS
=> 5V to 15 V
nominal voltage
=> up to 3 A
5V_USBPD
5V_USB_CHGR
5V nominal voltage
=> up to 1.5 A
5V_USB_CHGR
5V_USB_STLK
5V_VIN
5V_USBPD
5V_VIN
5V nominal voltage
=> up to 1.5 A
BUCKS
+ RGB
POWER
LED
5V_OUT
LD39050
STM32G4
VDD
3V3_OUT
VREF
power
LD3985
3V3_OUT
5V_OUT
VBAT
VDD
VDDA
VREF+
5V_SEL
STLINK /
V3E
3V3_STLK
POWER
DIAGRAM
=> Up to 150 mA
Up to 1.5 A
=> Up to 10 mA
=> Up to 500 mA
=> Up to 500 mA
100 mA
380 mA / 520 mA / 810 mA / 950 mA
Up to 500 mA
Double
switch
VOUT
embedded
resistor
LOADs
3V3
5V
T_NRST
Up to 1.5 A
370 mA
10 mA
Up to 1.5 A
VIN
VOUT
V_LED
R133
SB18 OFF
Up to 950 mA
Up to 0.5 A
Up to 1.5 A
SB38 ON
SB30 ON
Speaker
Option
USER LEDs /
JOYSTICK
30 mA
TEXT Connector
=> 3V to 16 V
Up to 500 mA
(externally)
Power voltage
and/or current
consumption
SB31 ON
150 mA
CN2 CN3
CN9 CN8
For detailed BUCK-BOOST limits,
refer to dedicated application note
CNx
JP1
CN7
JP2/JP3
JP5
JP4
JP7
=> Up to 250 mA
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UM2577

10.2 Power source selection
The B-G474E-DPOW1 product is designed to be powered by a 5 V DC power supply. It is possible to configure
the Discovery board with JP5 header to use any of the four sources described in Table 6 for the 5 V DC power
supply.
Table 6. JP5 5V_SEL configuration
Reference Jumper(1) Function Comment
JP5
STLK 5 V is supplied from USB STLK
CN3
• 5 V (+/- 5 %),
• 700 mA embedded overcurrent protection
• Up to 500 mA capable
CHGR 5 V is supplied from USB STLK
CN3
• 5 V (+/- 5 %)
• No embedded current protection
• Up to 1.5 A current
USBC
5 V is supplied from LTC3114-1
5 V converter (Power source
connected to USB Type-C® CN2
connector)
• 5 V (+/- 3 %)
• Embedded selectable current protection:
– Up to 950 mA on 5 V
– Up to 1.5 A from USB Type-C® VBUS
• USB Type-C® VBUS nominal voltage from 5 V
to 15 V
E5V 5 V is supplied from 5V_I pin of
CN9 extension connector
• 5 V (+/- 5 %)
• No embedded current protection
• Up to 1.5 A current
1. The default setting is in bold
In all below four power sources configuration, the LED LD7 5V and LED LD6 3V3 must be lit when the B-G474E-
DPOW1 product is correctly powered by the 5 V.
10.2.1 STLK
Figure 12 shows the selection of 5V from STLK on JP5, with a power source connected to USB ST-LINK (CN3). It
is the default setting.
The CN3 ST-LINK USB connector (STLK) can power the B-G474E-DPOW1 Discovery kit, but the host PC only
provides 100 mA to the ST-LINK circuit until the end of USB enumeration. At the end of the USB enumeration, the
B-G474E-DPOW1 Discovery kit asks for 500 mA current to the host PC.
If the USB enumeration succeeds, a power switch STMPS2151STR powers the board with up to 500mA current.
This power switch also features a 700 mA current limitation to protect the PC in case of overcurrent on the board.
Note: In this mode, in case a wall charger powers the board, there is no USB enumeration. Therefore, the COM LED
LD9 remains OFF permanently, but the 700 mA protection is still active on the powered board.
Figure 12. JP5 (STLK) from CN3 (USB STLK)
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Power source selection
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