Datasheet

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Switching Characteristics
Operating Characteristics
Power-Up Considerations
(1)
SN74LVCC3245A
OCTAL BUS TRANSCEIVER
WITH ADJUSTABLE OUTPUT VOLTAGE AND 3-STATE OUTPUTS
SCAS585O – NOVEMBER 1996 – REVISED MARCH 2005
over recommended operating free-air temperature range (unless otherwise noted) (see Figure 1 through Figure 4 )
V
CCA
= 2.5 V V
CCA
= 2.7 V TO V
CCA
= 2.7 V TO
± 0.2 V, 3.6 V, 3.6 V,
FROM TO
V
CCB
= 3.3 V V
CCB
= 5 V V
CCB
= 3.3 V
PARAMETER UNIT
(INPUT) (OUTPUT)
± 0.3 V ± 0.5 V ± 0.3 V
MIN MAX MIN MAX MIN MAX
t
PHL
1 9.4 1 6 1 7.1
A B ns
t
PLH
1 9.1 1 5.3 1 7.2
t
PHL
1 11.2 1 5.8 1 6.4
B A ns
t
PLH
1 9.9 1 7 1 7.6
t
PZL
1 14.5 1 9.2 1 9.7
OE A ns
t
PZH
1 12.9 1 9.5 1 9.5
t
PZL
1 13 1 8.1 1 9.2
OE B ns
t
PZH
1 12.8 1 8.4 1 9.9
t
PLZ
1 7.1 1 7 1 6.6
OE A ns
t
PHZ
1 6.9 1 7.8 1 6.9
t
PLZ
1 8.8 1 7.3 1 7.5
OE B ns
t
PHZ
1 8.9 1 7 1 7.9
V
CCA
= 3.3 V, V
CCB
= 5 V, T
A
= 25 ° C
PARAMETER TEST CONDITIONS TYP UNIT
Outputs enabled 38
C
pd
Power dissipation capacitance per transceiver C
L
= 50, f = 10 MHz pF
Outputs disabled 4.5
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. To guard against such power-up problems, take these
precautions:
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.
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