Post by PeteS Post by RHRRC
I am looking for a linear regulator that can be readily set to ~10V for
a 12/24v automotive environment.
Running current ~200mA.
Any suggestions to avoid a phlethora of protection components?
Depends where in the automotive environment you are.
If you are behind some of the switched power systems, you won't have to
worry about load dump _too_ much. If you're on the battery side, you
have to take that (and a lot of other things) very seriously. (Things
like E-marking, for instance).
All the usual suspects make supposedly 'load-dump protected'
regulators, but I have my doubts.
I don't have a list handy (not currently at the office) but for a
parametric search use a minimum of 30V Vin (a 24V vehicle has a typical
run voltage of about 27.5V). If it's rated higher, all the better.
Input protection can be pretty simple if you get a 40V device; use a 32
- 36V transorb (or one designed for automotive load dump such as the
SM8S series), an electrolytic for energy storage (rated at 63V should
be fine behind a protector) and a ceramic or two for high frequency
The only extra component I see there is the input protector - hardly a
'plethora' of protection components.
Thanks for the response.
The problem is with a single SAD , say a 5KW device, with a nominal
clamping voltage of 33V, a classIII surge will limit at around 80V. A
30V part is *very* close to the limits for a 24V automotive system and
may not be within accepted limit extremes. Two or three parallel 1K5W
devices could keep this down to ~60V.
I am trying to avoid an inductor varistor resistor transorb capacitor
diode 60V regulator set up as I am running out of volts at the 12V end!
35 to 40V devices are fine in 12v systems with straightforward
protection. Problem is in 24V systems, which are 'harsher' than 2x 12v
systems, 70 to 80V devices would be necessary for similar protection to
Such dedicated auto devices were once available, typically with 100V
input, reverse, and load dump protection, but they now seem no more -
or at least I cant find one. Everyone uses switchers but this app
cannot do so at this time.
It is an 'e' product: there is no 'E' applicable