Light emitting diode (LED) junction temperature variation,aging and other issues will lead to drift color temperature,color and other parameters.Current analog dimming and pulse width modulation (PWM) dimming can not solve this problem.Study found that average current affect flux,and peak currents affect color temperature.Therefore,a PWM and pulse amplitude modulation (PAM) dimming technology is proposed.Without changing the average value of the driving current pulse,we adjust the current pulse amplitude to compensate the color temperature drift.A PWM and PAM LED driver is shown,the experiment verifies that when average current is equal,luminous flux are equal,color temperature change along with peak current.Therefore,a PWM and PAM modulation technique proposed can compensate color temperature drift in actual dimming process,solve the problem of color temperature drift caused by LED junction temperature variation,aging and other problems.