Hi all,
We designed a LED driver based on TPS92513HV.
Input: 48V, 3.3V PWM signal.
Output: 30V max, 1A.
Schematic attached
In green - current sense out after LPF. this signal go to MCU.
In yellow - LED output voltage.
Dimming at 50%.
as you can see there is large noise measured on current sense - 150mV peak to peak, this happen when the IC is switching (logic '1' PWM).
we need to reduce this noise that go to the MCU, we tried the following:
* increase output capacitance.
* changed inductors type (wire/mold).
* switching frequency increase or decrease and inductor inductance respectively.
we understand that measuring on low side is problematic but the amount of noise on GND is massive.
please advice.
