[hpsdr] ALEX - Input protection

[michael taylor]

Rather than worrying about meeting manufacturer's minimums, why not
use Vishay or Fairchild bi-directional TVSes such as from Mouser?

Fairchild Semi SA5V0CA

Voltage:	5 V
Vbr   6.4V min / 7.00V max
Vclamp  9V
Power:	500 W
Peak Surge Current:	48.5 A
Package / Case:	DO-15
Product Category:	TVS

"Fast response time; typically less than 1.0 ps from 0 volts to BV for
unidirectional and 5.0 ns for bidirectional."
<http://www.fairchildsemi.com/ds/SA/SA5V0CA.pdf>

$0.37 in 1's from Mouser, and in stock
<http://www.mouser.com/search/ProductDetail.aspx?R=SA5V0CAvirtualkey51210000virtualkey512-SA5V0CA>

-Michael, VE3TIX

 1186542396.0