ELECTRICAL CHARACTERISTICS (Voltages referenced to Vss) (Con’t)
Characteristic
SYMBOL
V
DD
Min
Switching Characteristics
(See Fig. 3)
RC Oscillator Frequency
f
osc
4.0
10.0
18.0
4.0
10.0
18.0
4.0
10.0
18.0
-
-
-
4.0
10.0
18.0
-
-
-
-
-
-
-
-
-
23
0
0
215
80
50
1.3
4.0
6.0
2.3
7.0
11.0
1.2
4.0
7.0
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
30
0
0
280
105
65
1.0
3.0
4.5
1.8
5.5
8.5
0.93
3.0
5.5
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
40
0
0
370
140
85
0.76
2.3
3.4
1.3
4.0
6.5
0.7
2.3
4.2
-
-
-
-
-
-
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
ns
ns
ns
ns
ns
ns
-
For prescale
factor S = 1 or 3000
or 3600
S = 32768
or
32768 X 60
-
-
-
C
L
= 50pF
Max
Min
Max
Min
Max
Unit
Condition
External Clock or
Crystal Oscillator
Frequency
f
ext
f
ext
TRIG Set-Up Time
A, B Set-Up Time
WB0 - WB7 Set-Up Time
Clock to Out Delay
t
1
t
2
t
3
t
4
+V
500K
A
1
+
V
500K
B 2
EDGE
DETECT
TRIG 18
500K
RESET 7
CLOCK/RC/XTLI 4
LATCH
CONTROL
LOGIC
BUF
9 OUT
MODE
REG
500K
CLOCK
LATCH/TIMER
8
10-17 WB7-WB0
500K (8)
OSC
MUX
PRESCALER
XTLO(LS7212)
5
RCS/CLKS(LS7211)
5
500K
+V
1M
+V
-V (Gnd)
3-STATE
DECODER
1M
3 V
DD
8 V
SS
PSCLS
6
FIGURE 2. LS7211/LS7212 BLOCK DIAGRAM
LSI [ LSI COMPUTER SYSTEMS ]
