Hi Guys,
I’m hoping someone can help me please.
I have a pretty expensive ($1000+) electronics module to repair which has a tiny DC-DC convertor on board to run two seperate 5 volt outputs.
One supply runs the micro etc and the other runs the communications section.
There is a small 3mm square 8 pin driver IC with the label “MNAJ S14B” (on two lines) .. which drives an IRFR220 Mosfet.
Both are faulty and while the Mosfet is readily available … I cant find any reference to the IC anywhere !!! … despite hours on the net.
I have drawn out the circuit and the following are the pin outs …
Pin 4 & 5 go to ground
Pin 8 is the supply (22volt)
Pin 6 is the drive to the MOSFET Gate
Pin 1 connects to the MOSFET Source .. which also has a pair of 1 ohm
resistors in parallel to ground .. current monitoring I assume.
Pin 3 has a 20k to gnd. and an 84.5k resistor to the secondry of the transformer
Pin 7 .. also has a 84.5k resistor to another point in the secondry
Just wondering if anyone recognises the IC number … or the connections.
The board has the date of 2001 printed on it, so is not particularly old, and it was built in the US.
Hoping someone can help.
Regards, Wes.
I’m hoping someone can help me please.
I have a pretty expensive ($1000+) electronics module to repair which has a tiny DC-DC convertor on board to run two seperate 5 volt outputs.
One supply runs the micro etc and the other runs the communications section.
There is a small 3mm square 8 pin driver IC with the label “MNAJ S14B” (on two lines) .. which drives an IRFR220 Mosfet.
Both are faulty and while the Mosfet is readily available … I cant find any reference to the IC anywhere !!! … despite hours on the net.
I have drawn out the circuit and the following are the pin outs …
Pin 4 & 5 go to ground
Pin 8 is the supply (22volt)
Pin 6 is the drive to the MOSFET Gate
Pin 1 connects to the MOSFET Source .. which also has a pair of 1 ohm
resistors in parallel to ground .. current monitoring I assume.
Pin 3 has a 20k to gnd. and an 84.5k resistor to the secondry of the transformer
Pin 7 .. also has a 84.5k resistor to another point in the secondry
Just wondering if anyone recognises the IC number … or the connections.
The board has the date of 2001 printed on it, so is not particularly old, and it was built in the US.
Hoping someone can help.
Regards, Wes.