Maxim offers better PSRR (80dB vs. 65dB for Analog Devices AD1994)
Higher efficiency (87% vs. 80% for AD1994)
Spread-Spectrum modulation for lower EMI
Differential audio inputs instead of single ended compared to the AD1994. Offered in a 8x8mm package vs. a 9x9mm package for the AD1994. The AD1994 requires 8 external clamp diodes.