A programmable LF voltage ratio transformer using CMOS switches

A programmable 12-bit voltage ratio device having a voltage rating of 0.1 times frequency and a terminal linearity error of less than 1 × 10
⁻⁷
at 10–80 Hz is described. The compact design incorporates a 3-stage ratio transformer and it accommodates the use of solid-state switches having an ON-resistance of 100 Ω.