A simple single-stage variable gain amplifier that offers 86 dB of gain variation, consumes 1.4 mW, and occupies 0.07 mm(2) is introduced and shown to have the largest gain range, lowest power, and smallest chip size ever reported based on 0.18 mu m CMOS technology. A new approximated exponential equation is proposed, which offers the largest dB-linear range compared to all previously-reported approximated equations.