HD44780U Datasheet, PDF (55/59 Pages) Hitachi Semiconductor – Dot Matrix Liquid Crystal Display Controller/Driver

HD44780U
6. Applies to input pins and I/O pins, excluding the OSC1 pin.
7. Applies to I/O pins.
8. Applies to output pins.
9. Current flowing through pull–up MOSs, excluding output drive MOSs.
10. Input/output current is excluded. When input is at an intermediate level with CMOS, the excessive
current flows through the input circuit to the power supply. To avoid this from happening, the input
level must be fixed high or low.
11. Applies only to external clock operation.
Oscillator
OSC1
Open
OSC2
0.7 V_CC
0.5 V_CC
0.3 V_CC
Th
Tl
t _rcp
t _fcp
Duty = ^Th × 100%
Th + Tl
12. Applies only to the internal oscillator operation using oscillation resistor R_f.
OSC1
R_f
OSC2
R _f : 75 kΩ ± 2% (when V_CC = 3 V)
R _f : 91 kΩ ± 2% (when V_CC = 5 V)
Since the oscillation frequency varies depending on the OSC1 and
OSC2 pin capacitance, the wiring length to these pins should be minimized.
V_CC = 5 V
500
400
300
(270)
200
100
50
(91)₁₀₀
R _f (kΩ)
max.
typ.
min.
150
V_CC = 3 V
500
400
300
(270)
200
100
max.
typ.
min.
50 ⁽⁷⁵⁾ 100
150
R _f (kΩ)
55