I'm using the LMZ36002 buck converter module, which is a 1 MHz 4.5-60 V 2 A buck module. This means there is already an integrated inductor in the chip package. This device will accept any voltage between ~6V and 60V and regulates it down to my desired 5 V, 1.5 A board supply.
Normally, this device is run on 24 V DC from line power supply. Now I would like to add AC functionality by rectifying and smoothing the input.
My calculations are as following: (efficiency corrections are ignored)
- 5 V @ 2 A = 10 W
- 24 VAC * 1.414 = 34 V
- 10 W @ 34 V = 300 mA
I've simulated a circuit with diodes and one 470 uF capacitor in LTspice.
The load is a 70 ohm resistor. The ripple voltage on the rectified output is quite large, around 6-8V, but well within the buck converter's input range. Since space is an issue in this project, low capacitance like 470 uF would be preferred.
- Will this large ripple voltage cause any problems for the DC-DC converter?
- Could there be any serious problems, aside from degraded efficiency?