SUMMARY

• Successive approximation A/D converters are used routinely in applications of 1 MHz or less.
  
  
• For higher rates, parallel or flash converters are used. These perform comparisons in parallel. The hardware is more complicated, but the conversion time is much smaller. The number of bits per sample are more limited (typically 12 bits or less), but the sample frequency range can extend into the 1 GHz range (useful for digital communications systems).
  
  
• Flash converters can be cascaded to achieve better performance.
  
  
• Click here for a typical datasheet for an A/D converter.