Datasheet
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Switching Characteristics
Operating Characteristics
Power-Up Considerations
(1)
SN74LVCC4245A
OCTAL DUAL-SUPPLY BUS TRANSCEIVER
WITH CONFIGURABLE OUTPUT VOLTAGE AND 3-STATE OUTPUTS
SCAS584M – NOVEMBER 1996 – REVISED MARCH 2005
over recommended operating free-air temperature range, C
L
= 50 pF (unless otherwise noted) (see Figure 1 through
Figure 4 )
V
CCA
= 5 V ± 0.5 V, V
CCA
= 5 V ± 0.5 V,
FROM TO
V
CCB
= 5 V ± 0.5 V V
CCB
= 2.7 V to 3.6 V
PARAMETER UNIT
(INPUT) (OUTPUT)
MIN MAX MIN MAX
t
PHL
1 7.1 1 7
A B ns
t
PLH
1 6 1 7
t
PHL
1 6.8 1 6.2
B A ns
t
PLH
1 6.1 1 5.3
t
PZL
1 9 1 9
OE A ns
t
PZH
1 8.3 1 8
t
PZL
1 8.2 1 10
OE B ns
t
PZH
1 8.1 1 10.2
t
PLZ
1 4.7 1 5.2
OE A ns
t
PHZ
1 4.9 1 5.2
t
PLZ
1 5.4 1 5.4
OE B ns
t
PHZ
1 6.3 1 7.4
V
CCA
= 5 V, V
CCB
= 3.3 V, T
A
= 25 ° C
PARAMETER TEST CONDITIONS TYP UNIT
Outputs enabled 20
C
pd
Power dissipation capacitance per transceiver C
L
= 0, f = 10 MHz pF
Outputs disabled 6.5
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