User's Manual
Table Of Contents
- 1 Features
- 2 Product marking
- 3 System requirements
- 4 Development toolchains
- 5 Demonstration software
- 6 Ordering information
- 7 Hardware layout and configuration
- 7.1 Nucleo-68 board
- Figure 2. Nucleo-68 hardware block diagram
- Figure 3. Nucleo-68 board (top view)
- Figure 4. Nucleo-68 board (bottom view)
- Figure 5. Nucleo-68 board mechanical drawing
- Figure 6. Nucleo-68 board schematics
- Figure 7. Nucleo-68 board schematics - RF part
- Figure 8. Nucleo-68 board schematics - Connectors
- Figure 9. Nucleo-68 board schematics - Power management
- Figure 10. Nucleo-68 board schematics - ST-Link/V2-1
- 7.2 USB dongle
- 7.3 Getting started
- 7.4 Embedded ST-LINK/V2-1
- 7.5 Power supply and selection
- 7.6 Programing/debugging when the power supply is not from USB ST-LINK (5V_ST_link)
- 7.7 OSC clock sources
- 7.8 Reset sources
- 7.9 Virtual COM port: LPUART/USART
- 7.10 LEDs
- 7.11 Push buttons
- 7.12 Current measurement
- 7.13 Jumper configuration
- 7.1 Nucleo-68 board
- 8 Connectors
- Appendix A Nucleo-68 and USB dongle MCU IO assignment
- 9 Federal Communications Commission (FCC) and Industry Canada (IC) compliance statements
- 10 Revision history
UM2435 Rev 2 27/48
UM2435 Hardware layout and configuration
47
7.5 Power supply and selection
7.5.1 External power supply input
The Nucleo-68 board is designed to be powered by several DC power supplies. It is
possible to configure it to use any of the following power supplies by setting Jumper JP1:
• 5V_ST_LINK from STLINK USB connector (this is the default configuration)
• VIN (7 to 12 V) from Arduino™ connector or external connector CN4
• 5V_EXT from ST-Morpho connector
• 5V_USB from MCU USB (USB user)
• CR032 battery
The power supply capabilities are summarized in Table 5.
5V_USB_STLINK is a DC power with limitation from ST-LINK USB connector (USB type
microB connector of ST-LINK/V2-1).In the default setting JP1 needs to be on pin [7-8] to
select 5V_USB_STLINK power source on silkscreen of JP1. If the USB enumeration
succeeds, the 5V_ST_LINK power is enabled by asserting the PWR_ENn signal from
STM32F103CBT6. This pin is connected to a power switch (STMPS2141STR), which
powers the board. This power switch also features a current limitation to protect the PC in
case of currents exceeding 750 mA.
The Nucleo board and the shield on it can be powered from ST-LINK USB connector CN15,
but only ST-LINK circuit has the power before USB enumeration, because the host PC only
provides 100 mA to the board at that time. During the USB enumeration, Nucleo board
needs 500 mA from the host PC. If the host is able to provide the required power, the
enumeration finishes by a “SetConfiguration” command and then, the power transistor
STMPS2141STR is switched ON, the red LED (LED5) is turned ON, and the Nucleo board
Table 5. Power sources
Input name Connector Voltage range
Maximum
current
Limitations
5V_USB_STLINK CN15
4.75 to 5.25 V 500 mA
Maximum current depends upon
the USB wall charger used to
power the Nucleo-68 board
5V_USB_USER CN1
Maximum current depends upon
USB enumeration:
– 100 mA without enumeration
– 500 mA with enumeration
VIN
CN6 Pin 8
CN4 (SB24 on)
7 to 12 V 800 mA
From 7 to 12 V only
Input current capability linked to
input voltage:
– 800 mA when V
in
= 7 V
– 450 mA when 7 V < V
in
< 9 V
– 300 mA when 9 V < V
in
< 10 V
– < 300 mA when V
in
> 10 V
5V_EXT CN7 PIN6 4.75 to 5.25 V 500 mA -
CR032 battery SK_BT1 - 230 mAh -