The MSTHDA-1 is a single chip 1/6th octave-wide five harmonic Total Harmonic Distortion analyzer whose center frequencies are controlled by a single master clock. The center frequencies are at the fundamental, second harmonic, third harmonic, fourth harmonic and fifth harmonic frequencies. The sample to corner is 25:1 for the fifth-harmonic output and 125:1 at the fundamental output (double sampled). The fifth harmonic output is 3.4 MHz when clocked at 42.5 MHz.

The MSTHDA-1 includes two uncommitted op amps for adding additional fixed gain for microphone or other low level applications. A digitally programmable gain stage provides 0, 10 or 20 dB of gain. The PD pin selects power down, low power for ultrasonic applications and regular power for high frequency operation.

The MSTHDA-1 is fabricated in 0.6 um CMOS process for low power consumption and operation from 3.0 to 5.5 VDC


  • Selectable Power Modes as low as 2 mA (3V)
  • Power Down Mode to 400 uA
  • Operates from 3.0 V to 5.5 VDC
  • Five 6 pole Bandpass filters in one package
  • Digitally controlled gain stage
  • Two uncommitted Op Amps
  • No Microprocessor Needed


  • Multi-standard RFID Readers
  • Real-Time Distortion Analysis
  • Audio and Ultrasonic Analysis
  • Vibration Analysis