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Turnon Sequencing Example

under Configure in Figure 3 are changed to Mode 1 settings. Another write to hardware is done, and then

all supplies are sequenced without turning the board off and on. When all boards need to be sequenced

off by a specified delay setting, then all enable polarities can be reset to Mode 2 and a write to the

hardware can be repeated. This then sequences all supplies off, based on the specified time for each

supply.

2.4 Voltage Monitoring

The last Fusion GUI readout beneficial for maintaining correct output voltage levels is the voltage

monitoring function. This portion of the software allows real-time voltage monitoring of each output voltage

rail. In Figure 5, the output voltage readings appear in the top left. Each voltage reads out the correct

output voltage of each supply. The monitoring is preprogrammed based on the hardware and software

specifications. The voltage reading for Vout #6 – NEG Rail is not valid because the monitor pin was not

connected for this rail. This is because the output of the negative regulator is -5 V and cannot be divided

appropriately to a voltage within the 0V to 2.5V requirement.

When monitoring voltage it is important whether the voltage exhibits undervoltage or overvoltage

conditions. Measure this data within the Status Registers/Lines box or the graphical readout for the

respective output voltage to the right of the Readings box. These two boxes indicate if the output voltage

is OK, as well as what condition the voltage is in with respect to the overvoltage and undervoltage limit

conditions. This data ensures the power supply board is operating correctly.

Figure 5. Voltage Monitoring Readouts For Each Output Voltage Rail

3 Turnon Sequencing Example

To verify the sequencing of two of the supplies turning on, perform the following steps for setting up the

TSW2200 and the Fusion GUI software. For this setup, the 5V rail does not have a turn on delay, whereas

the 3.3V rail has a 20ms delay.

SLWU081A–May 2012–Revised December 2012 TSW2200EVM: Multi-Output Power Supply Evaluation Module

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