JAJSMG4A June 2023 – September 2023 TPS922052 , TPS922053 , TPS922054 , TPS922055
PRODUCTION DATA
The TPS92205x family supports a unique hybid dimming function to maximize the dimming performance, especially when both high dimming frequency and high dimming ratio are needed. The hybrid dimming mode is enabled when the ADIM/HD pin is always low and the EN/PWM pin is configured by a PWM input signal.
In the hybrid dimming mode, the LED current is regulated by the analog dimming at high brightness level (12.5% to 100%) and by the PWM dimming at low brightness level (0% to 12.5%), respectively. At high brightness level, the internal voltage reference, VREF, changes in proportion to the duty cycle of the PWM input signal at the EN/PWM pin with 8-bit resolution. At low brightness level, VREF stays unchanged and an internal PWM generator is enabled. Thus, the LED is turned on and off corresponding to the on and off of the internal PWM signal of which the frequency and the duty cycle are configured by the PWM input signal at the EN/PWM pin. In addition, the internal PWM signal has a 0.4% hystersis response when the PWM input duty cycle changes between increasing and decreasing. The detailed hybrid dimming behavior is illustrated in the below figure.