UPD16431A NEC, UPD16431A Datasheet - Page 7

• Manufacturer Part Number: UPD16431A
• Description: 1/2/ 1/3/ 1/4-DUTY LCD CONTROLLER/DRIVER
• Manufacturer: NEC

affected or ICs may be damaged or deteriorated.
cause not only current I
It is possible that this will then cause the following three problems:
If diode A is not available, not only the key data may not be read normally but the LCD display may be
For example, if SW1 and SW2 are ON and KS
(1)Since the level to KEY
(2)If KS
(3)Since the short-circuited current (current I
to light up).
damaged or deteriorated
KEY
KEY
KEY
KEY
2
is used as SEG
I
1
2
1
3
4
Select
(high level)
KS
1
SW1
I
2
1
KS
which is supposed to run but also short-circuited current I
2
2
SW2
as well, the LCD display may be distorted (such as causing unintended segments
2
is not correctly sent, the key data cannot be latched correctly.
KS
3
KS
4
Non Select
(low level)
KS
5
KS
1
2
) of KS
has been selected (high level) as shown below, this will
6
KS
7
2
(high level) to KS
KS
8
2
=
(low level) runs, ICS may be
2
of KS
PD16431A
1
to KS
2
to run.
7