The 3-wire serial interface is SPITM/QSPITM and MicrowireTM compatible. Each DAC has a doublebuffered input organized as an input register followed by a DAC register, which allows the input and DAC registers to be updated independently or simultaneously with a 16-bit serial word. Additional features include programmable shutdown (2A), hardware-shutdown lockout (PDL), a separate reference voltage input for each DAC that accepts AC and DC signals, and an active-low clear input (CL) that resets all registers and DACs to zero. These devices provide a programmable logic pin for added functionality, and a serial-data output pin for daisy chaining.