Datasheet

I
IN
V
IN
V
T
/4 kW
–(V
D
– V
T
)/4 kW
A. V
T
is the input threshold voltage of the TXB0104 (typically V
CCI
/2).
B. V
D
is the supply voltage of the external driver.
TXB0104
www.ti.com SCES650F –APRIL 2006–REVISED MAY 2012
Figure 2. Typical I
IN
vs V
IN
Curve
Power Up
During operation, ensure that V
CCA
≤ V
CCB
at all times. During power-up sequencing, V
CCA
≥ V
CCB
does not
damage the device, so any power supply can be ramped up first. The TXB0104 has circuitry that disables all
output ports when either V
CC
is switched off (V
CCA/B
= 0 V).
Enable and Disable
The TXB0104 has an OE input that is used to disable the device by setting OE = low, which places all I/Os in the
high-impedance (Hi-Z) state. The disable time (t
dis
) indicates the delay between when OE goes low and when the
outputs acutally get disabled (Hi-Z). The enable time (t
en
) indicates the amount of time the user must allow for the
one-shot circuitry to become operational after OE is taken high.
Pullup or Pulldown Resistors on I/O Lines
The TXB0104 is designed to drive capacitive loads of up to 70 pF. The output drivers of the TXB0104 have low
dc drive strength. If pullup or pulldown resistors are connected externally to the data I/Os, their values must be
kept higher than 50 kΩ to ensure that they do not contend with the output drivers of the TXB0104.
For the same reason, the TXB0104 should not be used in applications such as I
2
C or 1-Wire where an open-
drain driver is connected on the bidirectional data I/O. For these applications, use a device from the TI TXS01xx
series of level translators.
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