Quectel SC66 Hardware Design page 72

Smart LTE Module Series
SC66 Hardware Design
GPIO_40 238 DO LCD1 PWM output Used as a GPIO by default
The following are the reference designs for LCM interfaces. LCM can use external backlight drive circuit
according to customer requirement. The reference design of the external backlight drive circuit is shown
in the figure below, in which pins PWM (Pin 152 & Pin 238) can be used for backlight brightness
adjustment.
VPH_PWR
LCM0 _LED+
Backlight
Driver
PWM
LCM0_LED-
C1
2.2uF
Module
Figure 22: LCM0 External Backlight Driver Reference Circuit
VPH_PWR
LCM1 _LED+
Backlight
Driver
GPIO_40 LCM1_LED-
C1
2.2uF
Module
Figure 23: Reference Circuit Design for LCM1 Interface
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