NJU6625 New Japan Radio Co.,Ltd, NJU6625 Datasheet - Page 13

• Manufacturer Part Number: NJU6625
• Description: Nju6625 12character 1-line Dot Matrix Lcd Controller Driver With Smooth Scroll Function
• Manufacturer: New Japan Radio Co.,Ltd

Ver.2008-03-21
C) Example 2: Power supply changes
The NJU6625 is using between the keyscan terminal (K0~K3) and the terminal segment combined.
Therefore, the input protection diode is connected between V
circuit:A). If the power-supply voltage value is specified as V
ratings: Note3), NJU6625 operate normally. However, in case of the power-supply voltage is vary from the
spec, during the period of power supply rise, and please note the following points.
Key data input terminals (K0~K3) are pulled up to V
of V
voltage of the key input terminal lowers more than V
NJU6625 is “L” level. In addition, even if the key is not pushed, REQ=”H” is output.
Therefore in case of the power-supply voltage is V
this V
a) Keyscan input circuit (K0~K3)
b) Example 1: Power supply rising (Power ON)
Notes of the Keyscan
K
K
0
K
V
REQ
~K
V
REQ
LCD
0
V
LCD1
0
V
LCD1
~K
LCD
~K
DD
DD
<V
3
3
<V
3
DD
DD
, the current flow to the protection diode A, The voltage of the key input terminal falls. The
A
period, Key data must not be read.
V
V
LCD1
SS
V
V
IH2
VF
IH2
Preliminary
Maximum 1 frame
V
DD
Maximum 1 frame
Pull up
LCD
DD
Internal
Circuit
<V
IH2
during the period of keyscan (t
DD
(Electrical characteristics), and it is judged that
, during the period of power supply rise, during
LCD1
V
supply rising (Power-ON). In addition, t o
release the request, it is necessary by one
frame or less (Period from rising of V
voltage of terminal K0~K3 to release of
REQ).
In case of the power-supply voltage is
V
supply changes. In addition, to release the
request, it is necessary by one frame or
less (Period from rising of V
of terminal K0~K3 to release of REQ).
LCD1
In case of the power-supply voltage is
in the key input terminal (1 Keyscan input
V
LCD
LCD
level and that REQ=”H” is output.
LCD
>V
<V
<V
+VF(=0.4V)<VIH2 It is judged the “L”
LCD2
DD
DD
, during the period of power
, during the period of power
>V
DD
>V
SS
KS
(Absolute maximum
). However, in case
NJU6625
IH2
by voltage
IH2
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by