Semi-Trailer Power Supply..

[shawnmulligan]

I'm open to input...

for the design of a power supply to operate in a diesel, semi-trailer
environment. The circuit operates on 5V at 150mA with peaks of 400mA.
The actual device includes 3 microcontrollers, some analog, a DAC, SPI,
I2C, RS232, 38,400 baud comms with a satellite receiver, and SPI comms
with a wired keypad.

This is a busy design in a noisy/harsh environment internally and
externally.

The previous designer chose the LM2937ET - 5.0 but this a big task to
ask for such an LDO and I'm not happy with the heat generated or
parasidic power draw from the battery when the vehicle is parked.

Ideas welcome. shawn

 

[James Beck]

I'm open to input...

for the design of a power supply to operate in a diesel, semi-trailer
environment. The circuit operates on 5V at 150mA with peaks of 400mA.
The actual device includes 3 microcontrollers, some analog, a DAC, SPI,
I2C, RS232, 38,400 baud comms with a satellite receiver, and SPI comms
with a wired keypad.

This is a busy design in a noisy/harsh environment internally and
externally.

The previous designer chose the LM2937ET - 5.0 but this a big task to
ask for such an LDO and I'm not happy with the heat generated or
parasidic power draw from the battery when the vehicle is parked.

Ideas welcome. shawn

Plenty of switch mode simple switcher (TM National I'm sure) IC's that
have ON/OFF pins that put them to sleep at the uA level. The LM2574 P+
will give you ~500mA with a a bit more efficiency, with 13V in and 5V
out I wouldn't think that a LDO regulator is as important than the
ability to handle the crap that an automotive environment is prone to.
Anyway, do a little searching on National, Micrel, TI and others. Lots
of options out there.

Jim

 

[shawnmulligan]

Thanks Jim.