AC CHARACTERISTICS (VCC = 4.5 to 5.5 V, TA = – 40 to + 85°C, unless otherwise stated)
Parameter
Symbol
Min
Typ
Propagation Delay Input to Output (S1 Open)
tPLH
—
6
tPHL
Output Skew (S1 Open)*
Skew
—
1.0
Differential Output
Rise Time
Fall Time (S1 Open)
tTLH
—
4
tTHL
Output Enable Time
(S1 Closed)
tPZH
—
16
tPZL
—
15
Output Disable Time
(S1 Closed)
tPHZ
—
6
tPLZ
—
9
* Skew: difference in propagation delays between complementary outputs.
AC TEST CIRCUIT AND SWITCHING TIME WAVEFORMS
Max
Unit
12
ns
4
ns
8
ns
—
ns
—
—
ns
—
INPUT
47 pF
1.5 V
47 pF 49.9 Ω
499 Ω
S1
47 pF 49.9 Ω
Figure 1. AC Test Circuit
3V—
ENABLE INPUT
1.5 V
0V
tPLZ
tPZL
OUTPUT A
VOL + 0.5 V
OUTPUT B
tPHZ
tPZH
VOH – 0.5 V
1.5 V
— 1.5 V
0.8 V
VOL
VOH
2.0 V
— 1.5 V
Figure 3. Enable and Disable Times
3V—
INPUT
0V
1.5 V
tPLH
OUTPUT A
1.5 V
OUTPUT B
SKEW
tPHL
1.5 V
tPHL
tPLH
1.5 V
— VOH
1.5 V
VOL
VOH
1.5 V
— VOL
Figure 2. Propagation Delays and Skew Waveforms
3V—
INPUT
0V
OUTPUT
(DIFFERENTIAL)
90%
10%
tTLH
90%
10%
tTHL
Figure 4. Differential Rise and Fall Times
ENABLE
DATA
TYPICAL APPLICATIONS
+
–
DATA
OUTPUT
Figure 5. Two–Wire Balanced Systems (EIA–422–A)
MOTOROLA
MC34C87
3