VFC Power Supply Test
The VFC Power Supply Test can be split up in two parts:
-
Visual inspection carried out by the operator
This method is prone to be buggy due to several psychological factors (laziness, looseness, ...). This kind of test is particularly important for fast debugging. -
Automatized power supply test
By communicating with two SPI devices we can know exactly the values of all the voltages domains
Automatized power supply test
Here is the table with the power domains to be tested:
VCC net | Nominal voltage | Min voltage | Max voltage | Comments |
V3P3FMC1 | 3.3V | 2V | 3.6V | Used in FMC SPI connection and JTAG, hence LVTTL are taking as reference |
V3P3FMC2 | 3.3V | 2V | 3.6V | Used in FMC SPI connection and JTAG, hence LVTTL are taking as reference |
V12P0FMC1 | 12V | 11.64V | 12.6V | Bypassing 12V from VME bus |
V12P0FMC2 | 12V | 11.64V | 12.6V | Bypassing 12V from VME bus |
VADJ1 | Adjustable | Programmable via SPI | ||
VADJ2 | 2.5V | Nothing to do |
The way of running the test is communicating with the IC14, a ADC AD7888AR device, via SPI and checking the thresholds. For VADJ1, it is a must configuring the IC44, a digital adjustable resistor MAX5483EUD+, in advance for setting the nominal voltage. The threshold will be then set depending on the required logic level.