  We formulate a family of algebras, twisted Yangians (of split type) in
current generators and relations, via a degeneration of the Drinfeld
presentation of affine $\imath$quantum groups (associated with split Satake
diagrams). These new algebras admit PBW type bases and are shown to be a
deformation of twisted current algebras; presentations for twisted current
algebras are also provided. For type AI, it matches with the Drinfeld
presentation of twisted Yangian obtained via Gauss decomposition. We conjecture
that our split twisted Yangians are isomorphic to the corresponding ones in RTT
presentation.
