HD66727 Datasheet, PDF (63/97 Pages) Hitachi Semiconductor – Low-Power Dot-Matrix Liquid Crystal Display Controller/Driver with Key Scan Function

HD66727
Example of Using Internal Operational Amplifier when Driving Large Size of LCD
The driving current of the internal operational amplifier in the HD66727 is reduced to control the
consumption current. When load current is apparently large such as when driving large size of LCD panel,
insert a capacitor between V1OUT–V5OUT outputs and V_CC power supply, and stabilize the output level of
the operational amplifier. Especially the capacitors for V1OUT and V4OUT must be inserted when 1/26
duty or 1/34 duty drives.
OPOFF = GND
0.1µF to 0.5µF*
V_CC
+ +++ +
V_CC
R
HD66727
V_CC
V1OUT
+
–
V1
V2 ^R
V2OUT
R
V3 ^R
V3OUT
R
V4OUT
+
–
V2
LCD
multiplexing
driver
+
–
V3
+
–
V4
R
V5OUT
+
–
V5
VR
V_EE
Vci
C1
0.47 µF
to 1 µF ₊ C2
V5OUT2
Booster
+ ^{0.47 µF}
to 1 µF
GND
V5OUT3
Large size of LCD panel
SEG1–SEG60
COM1–COM16
COMS1–COMS2
+ ^{0.47 µF}
to 1 µF
GND
Note : The capacitors for V1OUT and V4OUT must be inserted when 1/26 duty or 1/34 duty drives.
Figure 36 Operational Amplifier Output Stabilization Circuit Example when Driving Large Size of
LCD Panel
63