Instructions

USB Connector

TPS62237

DC-DC Converter

Isolation

Jumper Block

eZ-FET lite 5V

eZ-FET lite 3.3V

5V in

3.3V out

MSP430F5529 Target

5529 Target + BoosterPack 5V

5529 Target + BoosterPack 3.3V

MSP430F5529

Target Device

eZ-FET lite

* 3V3 Isolation

Block Jumper

Disconnected

Hardware

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2.4.1 External 3.3-V Power Source

It is often beneficial to evaluate the LaunchPad with an external power source (see Figure 18). To see

accurate system power when performing this action, it is best to disconnect all jumpers in the isolation

block, so that additional power is not consumed by back-powering the emulation MCU through its I/Os.

The 5-V jumper can be left populated for proper USB operation and to allow for 5 V to the target side.

Figure 18. Power Block Diagram for External 3.3-V Power Source

1. Disconnect the 3V3 jumper in the isolation jumper block. This should be done regardless of 5-V source

(external or USB), to avoid conflict with the eZ-FET lite 3.3-V rail.

2. If the target voltage to be applied is anything other than exactly 3.3 V, remove the SBW and SBW TST

jumpers. The emulator always runs at 3.3 V, and allowing the emulator to communicate with the target

when their voltages are significantly different results in back-powering and possible unexpected

behavior.

3. Apply the external power source to any appropriate location. This includes the 3V3 pin on the right-side

power header or directly to the 3V3 BoosterPack header pin.

Note that step 2 requires that emulation is not possible if you are using an external power source at a

voltage other than 3.3 V. But USB can be used under these conditions, because there is no connection

between the USB module's VBUS and VUSB rails and the DVCC and AVCC rails used by the rest of the

F5529.

MSP430F5529 LaunchPad™ Development Tool (MSP

‑

EXP430F5529LP) SLAU533A–September 2013–Revised January 2014

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