SLAU647O July 2015 – April 2020
All MSP debug probes can supply targets with up to 100 mA through pin 2 of the 14-pin JTAG connector.
NOTE
The target should not consume more than 60 mA at peak current, as it may violate the USB specification. Details can found on www.usb.org.
Example: If the target board has a capacitor on the VCC line with a capacity of more than 10 µF, it may cause an inrush current during capacitor charging that may exceed 60 mA. In this case, the current should be limited by the design of the target board, or an external power supply should be used.
Target VCC is selectable in a range between 1.8 V and 3.6 V in steps of 0.1 V.
Alternatively, the target can be supplied externally. In this case, the external voltage should be connected to pin 4 of the 14-pin JTAG connector. MSP-FET tools adjusts the level of the JTAG signals to automatically match the external VCC.
NOTE
Only pin 2 (MSP-FET tool supplies target) or pin 4 (target is externally supplied) must be connected. Both connections are not supported at the same time.
Even if an external supply powers the target device on the target socket module and any user circuitry connected to the target socket module, the MSP-FET tool continues to be powered from the PC through the USB interface.
NOTE
MSP-FET430PIF only
The PC parallel ports with a connected MSP-FET430PIF can source a maximum current of 25 mA. Because of the ultra-low-power requirement of the MSP430, a stand-alone MSP430 does not exceed the provided current. However, if additional circuits are added, the current limit could be exceeded. In this case, the MSP430 must be supplied externally.