Make sure you read through this thread too -
There are lots of details re: what to order, etc.
Between the two threads, the only major thing that seems to be missing is a discussion of Korean (your husband will be staying very close to the part of Santa Clara known on the CH Boards as Soondubu Row - a stretch of El Camino Real with lots of Korean restaurants, many of them serving spicy tofu casseroles). Here's the most recent comprehensive discussion that I recall.
He's also going to be very near Cupertino Village, an Asian food mall. I seem to always go to A&J for spicy beef noodles when I'm there, but if he enjoys exploring, that's a good place to start.
If I were eating alone in the South Bay, here's what I'd get (note - I haven't been to a lot of these places in a couple of years).)
Chez Sovan (Cambodian) - chicken soup, amok
Krung Thai - red duck curry, pad thai
Dasaprakash - upma
Udupi Palace - dosa
Kabob 'n Curry - chicken tikka masala
Gaesung House of Tofu - spicy seafood tofu casserole
Saravana Bhavan - whatever dinner tiffin they have that day
A&J - spicy beef noodle soup with knife shaved noodles
China Stix - you tiao and sweet dou jiang (weekends only, and you have to be pretty aggressive
Haven't been, but want:
ASJ - spicy beef noodle soup
Kahoo Ramen - shoyu ramen
Ay Chung - fuzhou style fish ball soup
99 Chicken - Korean fried chicken
Gaesung House of Tofu
2089 El Camino Real, Santa Clara, CA 95050
2110 El Camino Real, Santa Clara, CA 95050
4330 Moorpark Ave, San Jose, CA 95129
458 Barber Ln, Milpitas, CA 95035
1698 Hostetter Rd, San Jose, CA 95131
Saravana Bhavan USA
1305 S Mary Ave, Sunnyvale, CA 94087
Dasaprakash Indian Restaurant
2636 Homestead Rd, Santa Clara, CA 95051
Krung Thai Restaurant
580 N Winchester Blvd, San Jose, CA 95128
976 E El Camino Real, Sunnyvale, CA 94087
2425 S Bascom Ave, Campbell, CA 95008
2781 El Camino Real, Santa Clara, CA 95051
Kabab & Curry's
1498 Isabella St, Santa Clara, CA 95050
A & J Restaurant
10893 N Wolfe Rd, Cupertino, CA 95014
dbug31, you need not look further than daveena's response. A very comprehensive list to which I will only add Falafel Drive In, not far from where your husband will be staying (I don't think I saw this on that thread). There are also some In-N-Out Burgers in the area. Also, I'm sure your husband's colleagues will have suggestions (especially for inexpensive Mexican) and confirm anything on CH.
There's a lot of good, inexpensive food down there. Does he like Chinese/ Korean/ Japanese /Thai/ Cambodian/ Ethiopian/ Vietnamese? If yes, we can start giving specific recs.
Here's a good, recent thread you'll find helpful -
Plus, tell him to get a glazed, yeast raised donut from Stan's Donuts (2628 Homestead Rd, Santa Clara) at least once.