GUI Register Page
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SNVA481B – October 2011 – Revised January 2020
Copyright © 2011–2020, Texas Instruments Incorporated
AN-2143 LM5064 Evaluation Kit
Design inputs are keyed in on the left side following steps 1 though 5. General operating conditions should
be entered in step 1 of the design tool. These inputs help set bounds on the startup time and application
voltage ranges.
Step 2 allows the user to tailor the MOSFET protection features to be specific to the target application.
Current limit is pin-configurable and software configurable, and circuit breaker is software-configurable. If
CL switch is used to set the current limit, make sure the GUI selection matches the pin-configurable CL bit
setting on the board. By clicking on the MOSFET SOA Profile button the user can select SOA data from
several popular MOSFETs or enter the SOA data for the desired MOSFET. The resistor R
PWR
can then be
calculated to keep Q
1
within its SOA profile.
Step 3 allows the user to select the under- and over-voltage lockout values (UVLO/OVLO). Note that with
the correct values for R1 - R4, the device will indicate a fault condition when the input and/or output
voltages are outside of their programmed range.
Step 4 allows the user to set the fault time-out period and the fault response. The fault time-out should be
set to be below the MOSFET SOA data for a given time. For example, if a design is done to adhere to the
10 ms pulsed MOSFET SOA data, the desired fault time-out must be less than 10 ms. The fault time-out
time entered will set the value for C
T
. It also sets the insertion delay and fault retry delay. The initial power
up retry behavior is also selected in this design step. Make sure to change the RETRY switch to match the
design tool schematic when changing the default retry setting.
In step 5 the user enters the desired PMBus address. Note changing the PMBus address of the device in
step 5 does not change the device address, but shows how the address pins of the device need to be
configured to achieve a desired address. Once the ADR pin switches are configured for a particular
address, power to the device needs to be cycled and the GUI restarted in order for the new address to
take affect.
When invalid or incorrect inputs are given to the design tool, text associated with the faulty input will turn
red. Positioning the mouse cursor over the red text will give additional information about any design
conflict.
Component and parametric results are shown to the right as well as the LM5064 protection SOA chart.
The protection SOA chart shows the minimum, typical, and maximum SOA protection areas for a given
design. For a robust design, the SOA of the MOSFET used should be above the MAX protection SOA line
for all operating areas.
Once a design is complete, the design should be saved by selecting the File menu, and then Save. Once
the hardware is modified to match the design the GUI should be restarted and the hardware configuration
file loaded right after the device is detected and placed. If the values in the design tool are different than
the values on the board, erroneous telemetry and fault data will be reported by the GUI. To return to the
block view of the device, press the home icon located at the far left in the menu bar.
The design tool is also useful to calculate the PMBus coefficients. With the correct value for current sense
resistor (R
S
) the tool will calculate the correct coefficients to scale the raw telemetry data. The coefficients
can be viewed by selecting View from the main menu bar, and then selecting the PMBus Coefficient
Editor. When the PMBus Coefficient Editor is opened, press the Get All button to show the currently used
coefficients.
If desired the results presented by the design tool can be calculated by hand using the equations provided
in the datasheet. However, note the design tool calculates parameters factoring in worst case tolerances,
while the equations in the data sheet are based on typical thresholds.
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GUI Register Page
The GUI Register Page, as shown in
, provides the user with several features to help better
understand the functionality of the LM5064. These features include the ability to read telemetry, device
identification and status registers, as well as being able to monitor the SMBus Alert and PGOOD
interrupts, and to turn the output on and off with the OPERATION button.