This paper describes a novel multi-operand radix-2 signed-digit adder. The novel multi-operand addition algorithm can eliminate carry propagation chains by parting input operands into every two place block. The multi-operand adder with this algorithm can add four operands in parallel and operates much faster than the ordinary SD adder binary tree method. The paper presents a hardware model for the proposed adder, which is implemented by the current-mode MOSFET circuit technology.