HT1621
A.C. Characteristics
Symbol
f
SYS1
Parameter
System Clock
Test Conditions
V
DD
5V
f
SYS2
f
SYS3
System Clock
System Clock
3V
5V
3V
5V
¾
f
LCD
t
COM
f
CLK1
f
CLK2
LCD Clock
LCD Common Period
Serial Data Clock (WR pin)
Serial Data Clock (RD pin)
¾
¾
¾
3V
5V
3V
5V
¾
¾
3V
5V
Crystal oscillator
External clock source
On-chip RC oscillator
Crystal oscillator
External clock source
n: Number of COM
Duty cycle 50%
Duty cycle 50%
On-chip RC oscillator
CS
Write mode
Read mode
Write mode
Read mode
¾
¾
¾
¾
¾
Conditions
3V On-chip RC oscillator
Min.
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
3.34
6.67
1.67
3.34
¾
¾
¾
¾
¾
Typ.
256
256
32.768
32.768
256
256
f
SYS1
/1024
f
SYS2
/128
f
SYS3
/1024
n/f
LCD
¾
¾
¾
¾
2.0 or 4.0
250
¾
¾
¾
¾
120
120
120
100
100
Ta=25°C
Max. Unit
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
150
300
75
150
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
kHz
kHz
kHz
kHz
kHz
kHz
Hz
Hz
Hz
s
kHz
kHz
kHz
kHz
kHz
ns
ms
ms
ns
ns
ns
ns
ns
f
TONE
Tone Frequency
t
CS
Serial Interface Reset Pulse
Width
(Figure 3)
WR, RD Input Pulse Width
(Figure 1)
t
CLK
t
r
, t
f
t
su
t
h
t
su1
t
h1
Rise/Fall Time Serial Data 3V
Clock Width
(Figure 1) 5V
Setup Time for DATA to WR, 3V
RD Clock Width (Figure 2) 5V
Hold Time for DATA to WR, 3V
RD Clock Width (Figure 2) 5V
Setup Time for CS to WR, RD 3V
Clock Width
(Figure 3) 5V
Hold Time for CS to WR, RD 3V
Clock Width
(Figure 3) 5V
8
January 10, 2001
ETC [ ETC ]
