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Smart LTE Module Series
SC20 Hardware Design
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LCM_LED+
PWM
Module
2.2uF
Backlight
driving
circuit
LCM_LED-
VBAT
C1
Figure 22: Reference Design for External Backlight Driving Circuit
3.19. Touch Panel Interface
SC20 provides a set of I2C interface for connection with Touch Panel (TP), and also provides the
corresponding power supply and interrupt pins. The definition of TP interface pins is illustrated below.
Table 22: Pin Definition of Touch Panel Interface
The following illustrates a TP interface reference circuit, by taking the connection with TP interface on
LHR050H41-00 (IC: GT9147) from HUARUI Lighting as an example.
Pin Name
Pin No
I/O
Description
Comment
LDO6_1V8
125
PO
1.8V output power supply for
TP I/O power
Pull-up power supply of I2C.
1.8V normal voltage
LDO17_2V85
129
PO
2.85V output power supply for
TP VDD power
TP power supply.
2.85V normal voltage
TP_INT
30
DI
Interrupt signal of TP
TP_RST
31
DO
Reset signal of TP
Active low
TP_I2C_SCL
47
OD
I2C clock signal of TP
TP_I2C_SDA
48
OD
I2C data signal of TP