Connecting The Evm; Example Test Setup - Texas Instruments TPSM831D31 User Manual

Connecting the EVM

4 Connecting the EVM
When connecting the EVM for evaluation at high currents, care must be taken to use heavy gauge wire
that can safely conduct the currents as high as 120 A on VOUT_A and 40 A on VOUT_B. The length of
the output connections must be kept as short as possible to minimize the voltage drop in the wiring. Many
electronic loads cannot produce the desired load current if the voltage at their input terminals falls below
~700mV. The use of multiple loads connected in parallel, operated in constant current mode permits the
load current to be shared over multiple paths. This reduces the overall voltage drop and enables operation
to high currents and lower voltages before the loads reach their saturation point.
configuration that allows testing to 120 A on VOUT_A and 40 A on VOUT_B. A total of four 60 A-rated
electronic load modules are used in this setup. The input voltage wiring should be rated to handle at least
20 A of current. If the host input supply supports remote sensing, its use is recommended.
As an added precaution, the user of the EVM is strongly encouraged set the maximum current of
their host input power supply to no higher than 25A.
The TPMS831D31 module requires communication over the PMBus to allow for configuration, control, and
transmission of telemetry data. Connect the 10-pin ribbon cable from the USB Interface Adapter pod to the
PMBus Interface header (P1). Connect a USB cable from the pod to a USB port of a computer that has
the Fusion Digital Power Designer application loaded. If the pod is properly recognized by the computer,
LED D1 should light on the EVM.
Before launching the fusion digital power GUI software, apply input power to the EVM. Set the input
voltage in the range from 8 V to 14 V. Set any electronic loads to no-load. After power has been applied,
launch the GUI software using the Fusion Designer Online shortcut icon, if present. As the software loads,
it should detect the presence of the USB to GPIO pod and begin scanning for devices on the PMBus. It
should detect the EVM at address 105 (decimal), 69 (hex) on the bus. The EVM must be powered-up for
this device scan to be successful. The GUI may identify the device as a TPS53681. This is normal. That is
the device used as the controller in the module.
6
Using the TPSM831D31 Power Module Evaluation Module
Figure 2. Example Test Setup
Copyright © 2018, Texas Instruments Incorporated
www.ti.com
Figure 2 shows a test
SNAU240 – August 2018
Submit Documentation Feedback