...
- Verify enable condition on all 4 switches (can draw load from the output when enabled, can’t otherwise)
- Verify output current limit (2.4A)
- Verify the OC pin goes low in this condition
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
- 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
...
- Verify the 17V output can be enabled and disabled vis N-CH FET (can draw load from the output when enabled, can’t otherwise)
- Verify the analog output of the amplifier matches expectations
- Verify the TVS diode function protects against an oversimplification of signal
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