Hello,
in the past we have some troubles with AM3359 caused by wrong capacitance values on VDIG2, VAUX, and other power rails (power is supplied through TPS65910A3A1RSL, CPU is AM3359ZCZA80). We solved this by adding correct caps, here is the link for reference:
https://e2e.ti.com/support/processors/f/791/t/492026
In short - replacing incorrect 0.01uF on VDIG2 (and not on any other LDO, where they are also incorrect) with 2.2uF helps.
VDIG2 becomes correct look and feel without any pulsations and the CPU is working great.
But unfortunately we already have produced several hundreds of wrong boards.
Is there any possibility to correct this without actual capacitor replacement? For example, can we disable some of CPU's internal blocks powered by VDIG2?
Our schematic is based on swcu093d.pdf file, where VDIG2 is connected to VDDS_PLL_xx, VDDS_OSC, VDDS_SRAM_CORE_BG and VDDS_SRAM_MPU_BB.
Can any of these blocks be switched off to limit the current and help make LDO stable?
If not, Is there any other possibility? For example, can we make a short between VDIG1 and VDIG2 (both are 1.8V and we fortunately have big cap on VDIG1)?
