Other Parts Discussed in Thread: LMZM23601
QCL-DFB laser needs ultra clean supply. LMZM23601 following tps7a4700 are intended to be used to output the required voltage. But a problem occures: the PSSR of tps7a4700 is very low in 200KHz-2MHz frequnce interval and frequency of PWM switch regulaor is in this interval. So something has to be done to reduce the switch noise before LDO, or the ripple may unacceptable. Could you give me some suggestion to it?
Thanks a lot in advance.