TXB0101DBVT datasheet(10/18 Pages) TI

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A. V is the input threshold voltage of the TXB0101 (typically

/2.

V is the supply voltage of the external driver.

CCI

–(V – V )/4 k

V /4 k

Power Up

Enable and Disable

Pullup or Pulldown Resistors on I/O Lines

TXB0101

1-BIT BIDIRECTIONAL VOLTAGE-LEVEL TRANSLATOR

WITH AUTO DIRECTION SENSING AND

±15-kV ESD PROTECTION

SCES639 – JANUARY 2007

PRINCIPLES OF OPERATION (continued)

Figure 2. Typical IIN vs VIN Curve

During operation, ensure that VCCA ≤ VCCB at all times. During power-up sequencing, VCCA ≥ VCCB does not

damage the device, so any power supply can be ramped up first. The TXB0101 has circuitry that disables all

output ports when either VCC is switched off (VCCA/B = 0 V).

The TXB0101 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 (tdis) indicates the delay between when OE goes low and

when the outputs acutally get disabled (Hi-Z). The enable time (ten) indicates the amount of time the user must

allow for the one-shot circuitry to become operational after OE is taken high.

The TXB0101 is designed to drive capacitive loads of up to 70 pF. The output drivers of the TXB0101 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 k

Ω to ensure that they do not contend with the output drivers of the TXB0101.

For the same reason, the TXB0101 should not be used in applications such as I2C 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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TXB0101DBVT Datasheet(PDF) 10 Page - Texas Instruments