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SN74LVC4245A
OCTAL BUS TRANSCEIVER AND 3.3-V TO 5-V SHIFTER
WITH 3-STATE OUTPUTS
SCAS375H – MARCH 1994 – REVISED MARCH 2005
Switching Characteristics
over recommended operating free-air temperature range, C
L
= 50 pF (unless otherwise noted) (see Figure 1 and Figure 2)
PARAMETER
t
PHL
t
PLH
t
PHL
t
PLH
t
PZL
t
PZH
t
PZL
t
PZH
t
PLZ
t
PHZ
t
PLZ
t
PHZ
FROM
(INPUT)
A
B
OE
OE
OE
OE
TO
(OUTPUT)
B
A
A
B
A
B
V
CCA
= 5 V
±
0.5 V,
V
CCB
= 2.7 V to 3.6 V
MIN
1
1
1
1
1
1
1
1
1
1
1
1
MAX
6.3
6.7
6.1
5
9
8.1
8.8
9.8
7
5.8
7.7
7.8
ns
ns
ns
ns
ns
ns
UNIT
Operating Characteristics
V
CCA
= 4.5 V to 5.5 V, V
CCB
= 2.7 V to 3.6 V, T
A
= 25°C
PARAMETER
C
pd
Power dissipation capacitance per transceiver
Outputs enabled
Outputs disabled
TEST CONDITIONS
C
L
= 0,
f = 10 MHz
TYP
39.5
5
UNIT
pF
Power-Up Considerations
(1)
TI level-translation devices offer an opportunity for successful mixed-voltage signal design. A proper power-up
sequence always should be followed to avoid excessive supply current, bus contention, oscillations, or other
anomalies caused by improperly biased device pins. Take these precautions to guard against such power-up
problems:
1. Connect ground before any supply voltage is applied.
2. Power up the control side of the device (V
CCA
for all four of these devices).
3. Tie OE to V
CCA
with a pullup resistor so that it ramps with V
CCA
.
4. Depending on the direction of the data path, DIR can be high or low. If DIR high is needed (A data to B bus),
ramp it with V
CCA
. Otherwise, keep DIR low.
(1)
Refer to the TI application report,
Texas Instruments Voltage-Level-Translation Devices,
literature number SCEA021.
5
TI [ TEXAS INSTRUMENTS ]
