Test Plan (Board Labelled Jeremey, other board NOT tested!!)

Owned by Logan Hartford
Last updated: Jul 14, 2023
4 min read

Post-Assembly

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

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

Basic Powered Tests

General Tests:

Program microcontroller
Verify the TVS diode function protects against overvoltage on analog lines
Do a full system test with all of the rails powered and make sure nothing explodes

48V Power

Power onboard + touch test, verify components and the board itself does not get too hot
Verify all ICs, details, LEDs, etc. are powered on successfully. Communicate with all peripherals

STM:

Verify the enable pins (N-CH MOSFET gate) can be driven high and low (PC1, PC3, PC5, PA6)
Gate and source pins are reversed in the footprint
Verify the analog read of the current sense amplifier outputs (PC0, PC2, PA5, PA7)
Verify the analog read of the VBAT rail (PC4)

Electrical:

5V Power:

STM:

Electrical

Problems:

  • at 1A load, the 5V output is dropping to 4.3V

    • Actually even at the power supply input it is 4.3V, so maybe it’s the power supply

    • Does it even when connecting power supply directly to the reload, maybe power drop through wires

      • Ya it is, its 5v right at the power supply terminal but

  • Highside switched shut down the output at 2A not 2.3 or whatever

17V Power

STM:

Electrical:

Problem:

  • When 17V was powered without 48V, there was a leakage to 48V, only 100 ohms between the rails

    • IC VCC is 48, though it is measuring at 17

  • When 48V was supplied without 17V, nothing

  • When both 17V and 48V were connected, IC blew up, shorted 48V though the IC,

  • I think pull resistors on N-CH/P-CH load switch has the output enabled by default

    • No, they are off by default

Changes for Next Rev

  • R44 and R45 are 0603 and should be 0805

  • Change 0.1uF 10V to 50V for consistency (5V high side switched)

  • 3.3k (r2) 0603 part number

  • There are 16V, 50V and 100V 1uF caps on the board

  • It should probably double the power rating on the current sense resistors for the 24V buck

  • Add label to 3v3 led

  • N-Ch fet description says 340mS instead of 340 mA

  • Add polarity indicators to terminals

  • STM reset button footprint is wrong, shorts itself out

  • Add testpoint labels where convenient

  • SHDN on CAN should have a test point

  • RST pin on microcontroller should have testpoint w label

  • Add clippy testpoints to all of the voltage rails

  • reduce the small terminal through hole size for better alignment

  • Both 5V rail ADC pins do not go to ADC capable pins

  • Current sens +/- pin name wrong

  • N-CH footprint is wrong

  • LED doens’t work

  • 17V current sense should be supplier by 17V so it doesn’t blow up

  • Either combine the 5V rails or make sure all of the start up conditions are on the same 5V rail

  • Make the current gain max out at 1.8V, change out the TVs diode for one that hopefully works,

    • In the firmware, the STM should shutdown the output when the voltage reaches 1.8V so it has a margin of error to shut down the output before it becomes dangerous to the stm