Kawa Peltsek was one of the twenty five disciples of Guru Rinpoche. For the full biography, visit his page on the Treasury of Lives site. He is mentioned in many books in English as he was one of the great translators during this formative period.
He was responsible for translating key texts including Shantideva's Bodhicharyavatara. Khenpo Ngawang Pelzang relates this in The Nectar of Manjushri's Speech, and quotes Ngok Loden Sherab who said "Kawa, Chokro, Zhang are like the sun and moon together....Compared to them we are but fireflies".
He is also mentioned repeatedly in Gyalwa Changchub's Lady of the Lotus Born.
Jamgon Kongtrul also talks about Kawa Peltsek and the whole process of translation in Book Six Parts 1 & 2 of his Treasury of Knowledge.
Full bio on the Treasury of Lives: http://bit.ly/kawa-peltsek
TBRC Resources for Kawa Peltsek: http://tbrc.org/#!rid=P8182