Glitching on real world target with voltage regulator

Hello everybody,

I have some free time again, so I’m getting back to glitching. In the past I worked on CWLite, now I have moved on to Husky. I am currently trying to work on a real target, the NXP 5169 ( I am trying to do some voltage glitching but without success.

The initial scheme is similar to the following.

In red I have already highlighted the capacitors, what is not clear to me is if I have to remove them all or only the C9? VDDD is the digital circuit voltage supply, VDDA is for the analog part.

On the datasheet I saw also that there is a voltage regulator.


The device is powered from the VDDA and VDDD pins, each being decoupled with a 100 nF
ceramic capacitor. VDDA is the power supply to the analog circuitry; it should be decoupled
to ground. VDDD is the power supply for the digital circuitry; it should also be decoupled to
ground. In addition, a common 10 F tantalum capacitor is required for low frequencies.
Decoupling pins for the internal 1.8 V regulators are provided with each pin requiring a
100 nF capacitor located as close to the device as practical. VB_SYNTH and VB_DIG
require only a 100 nF capacitor. VB_RF1 and VB_RF2 should be connected together as
close to the device as practical, and require one 100 nF capacitor and one 47 pF
capacitor. The pin VB_VCO requires a 10 nF capacitor. See Figure 48 for a schematic

In this case, the capacitors positioned after the voltage regulator (substantially on the VB_XX lines, C2, C1, C4, C3, C7, C13) could affect the ability to perform glitching?

Furthermore, since I have the VB_XX pins available, does it make sense to glitch on the VDDD or does it make more sense to go and do it on the VB_XX after the voltage regulator?

Thank you in advance


I’d recommend going after the VB_XX pins because that’s what’s presumably hooked up to the core. We’ve got a similar setup with our F2/F4 targets, as those both have internal regulators. In that case, we have no capacitance on the VCAP pins (output of the internal regulator) and feed in 1.2V to those pins instead of using the internal regulator.


Thank yoy for the reply Alex.

Your advice is to remove the others capacitors on the 1.8V line? or both, the ones into the VDD and VB_XX lines?

I’d recommend just removing the VB_XX capacitors as the VDD ones should help with regulator stability. This might be something you have to experiment a bit with though.