ADA2200 - no SYNCO signal

Discussion created by aeromek on Feb 21, 2017
Latest reply on Jul 12, 2017 by Gauzz

Hi All,


I am trying to use ADA2200 as lock-in amplifier for research purposes. I connected LDR via Wheatstone bridge to omp amp (MCP602) where the output goes to INP. INNis connected to VOCM and to GND via capacitor. To CLKIN I am supplying signal via voltage divider (5V to 3V) at frequency of 11 kHz. RCLK goes to transistor (BC182L) which is connected to simple LED. OUTN is left floating. OUTP I connected to PicoScope and measured signal (always after reset - otherwise it doesn't work) looks ok, i.e. as in the manual. VOCM is 1.6V as it should be. Everything would be ok but signal measured at SYNCO is stable at 0 V. Does anyone knows what is the reason for this? In addition, when I touch CLKIN pin with PicoScope probe then the measured signal at OUTP becomes chaotic (random) to I need to do reset.