We are using AD5421 and AD5700 for HART transmitter with loop powered. power to other circuit component is provided by the AD5421. DVDD output is used to power up microcontroller, external ADC digital part, AD5700.Regout is used to power up the analog part of external adc and pressure sensor. While sending HART command 0 from HART master to our device, we are obsreving glitch in the FSK waveform between master and slave frames and at the same time this glitch is obsereved between loop- and com pins of AD5421. It shows that while sending command 0 AD5421 tries to pull more current from the loop. Can anyone help me out to get rid of this glitch in the FSK?