CREATE TABLE table_77680 ("Model number" TEXT, "sSpec number" TEXT, "Frequency" TEXT, "L2 cache" TEXT, "Mult." TEXT, "Voltage" TEXT, "Socket" TEXT, "Release date" TEXT, "Part number ( s ) " TEXT, "Release price  (  USD  ) " TEXT)

What's the voltage for the pentium dual-core e2140?
SELECT "Voltage" FROM table_77680 WHERE "Model number" = 'pentium dual-core e2140'
SELECT "Voltage" FROM "table_77680" WHERE "Model number" = 'pentium dual-core e2140'