I have been doing some project which worked for few months and then MOSFETs started burning. Here is detail of schematic:
So, we are using:
- NTD4963MT4G MOSFET (datasheet)
- some 1k and 10k resistors
Microcontroller is Atmel Atmega328(Arduino bootloader, basically Arduino) which communicates with TLC5940 and controls TLC's outputs. Those 16 outputs are connected to MOSFETS.
From output of TLC there in a 1k resistor in series with gate and there is also 10k pull-up transistor on gate(to turn off MOSFET faster). Source of the transistor is connected to ground. Drain of transistor is connected to the load. Positive terminal(+) of load is directly connected to power supply positive terminal.
Riref resistor on TLC is 2k, which equals at 31,5*1,24/2000 = 19mA per channel.
Actual load are LED lights. Power of LED light on each channel is max. 15W.
Behaviour(code at Atmega) is to do various things with outputs, blink, fade etc.
Thanks anyone who puts thier time into resolving this issue.
EDIT: here are more details I, seems to be, forgot:
- Vcc is chooseable. It can be 5V, in that case uC and TLC, but LEDs too, are supplied directly from power supply. It can be 12V, also, then via regulator 5V is used for uC and TLC, but on MOSFETs there are 12V.
- TLC frequency is default, which is (I think)517,2Hz
- Schematic shows FDD8780 just because they have same footprint. NTD4963MT4G are actually used.