SPI LVDS Master - Rev1 - Test Plan - 09/29/2022

Owned by Logan Hartford
Last updated: Sept 29, 2022
3 min read

Pre-Assembly

Prior to any assembly at all, verify there are no shorts on the manufactured board. This will help detect faulty manufactured boards before wasting time on assembly, as well as help diagnose shorts if they do appear later, as you will be certain it is not a manufacturing issue.

Verify power rails are not shorted to GND or with each other
Verify EN/RST/SHDN pins are not shorted to either GND or a power rail, unless it is supposed to be
Verify communication protocol lines (i.e. SDA & SCL for I2C, MISO MOSI SCLK & CS for SPI, etc.) are not shorted with each other, with a power rail, or GND

If any shorts are found, do not proceed to assembly with that board. If all units of the board contain shorts, it may mean the design was faulty somehow and will need to be fixed and remanufactured.

Post-Assembly

A series of checks to do after finishing assembling or receiving an assembled board:

Check all required components are assembled and DNP components are not assembled
Verify components oriented correctly (polarity, pin 1 designators, etc.)
Verify there are no bridges between parts/pins creating unwanted shorts
Verify general soldering quality - no stray solder, burns, etc., all pins and pads connected with enough solder

Unpowered Tests

Things to check before powering on the board at all. This mostly involves checking for shorts with the multimeter’s ohmmeter.

Verify power rails are not shorted to GND or with each other
Verify EN/RST/SHDN pins are not shorted to either GND or a power rail, unless it is supposed to be
Verify communication protocol lines (i.e. SDA & SCL for I2C, MISO MOSI SCLK & CS for SPI, etc.) are not shorted with each other, with a power rail, or GND

If any shorts are found, do not connect the board to a power supply. Locate and attempt to fix the cause of any shorts before continuing.

Basic Powered Tests

The purpose of these basic tests is to verify the basic functionality of the board when powering it on for the first few times. When powering on the board for the very first time, supply the nominal expected voltage input for the board and start with a very low current output (i.e. 0.1A). This is to avoid any overheating or destructive failures from undiscovered issues. Once the first power on is complete and the power rail voltages and board temperatures are verified to be OK, the input power can be increased.

Power on board + touch test, verify components and the board itself does not get too hot
Probe power rails, verify correct voltage
Verify all ICs, components, LEDs, etc. are powered on successfully. Communicate with all peripherals (if applicable)
Program microcontroller (if applicable)

This list is not exhaustive of everything that should be checked when the board is powered on. There will likely be things specific to each board that should be checked in the first couple times powering the board on. Review the board’s schematic and think of any basic functionality that would be good to check.

Performance Tests

Performance tests are meant to measure, record, and analyze how well the board does what it was designed to do. For example, if your board includes some form of power regulation, such as a buck converter, it should be tested to see how well it performs with regard to stability, efficiency, etc. These tests are specific to every board, so the examples provided below may not fit exactly with your board.

Ex. If a board includes a buck converter, some good performance tests would be:

Line regulation
Load regulation
Efficiency
Output ripple
Transient response
Measuring significant waveforms (i.e. SW, gate waveforms)