HD66523 Datasheet, PDF (15/19 Pages) Hitachi Semiconductor – (240-Channel Common Driver with Internal LCD Timing Circuit)

HD66523
Power Supply Circuit
The example of power circuit is shown in Figure 13. When you want to change contrast, both levels,
VRH and VRL must be changed.
V_CC
GND
VLCD
(variable)
VDD
(fixed)
DC/DC
Converter
VLCD
VRH (COM)
V_CC
–
+
VCH (SEG)
–
+
VM (COM, SEG)
–
+
VCL (SEG)
GND
V_EE
(variable)
V_EE
VRL (COM)
Note: VM level must keep following equations;
(VRH–VM) = (VM–VRL)
(VCH–VM) = (VM–VCL)
VCL > GND
VCH < VDD
Figure 13 Example of Power Supply Circuit
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