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PRINCIPLES OF OPERATION

Applications

Architecture

4k

4k

A

B

One

Shot

One

Shot

One

Shot

One

Shot

T1

T2

T3

T4

Input Driver Requirements

TXB0101

1-BIT BIDIRECTIONAL VOLTAGE-LEVEL TRANSLATOR

WITH AUTO DIRECTION SENSING AND

±15-kV ESD PROTECTION

SCES639 – JANUARY 2007

The TXB0101 can be used in level-translation applications for interfacing devices or systems operating at

different interface voltages with one another.

The TXB0101 architecture (see Figure 1) does not require a direction-control signal to control the direction of

data flow from A to B or from B to A. In a dc state, the output drivers of the TXB0101 can maintain a high or low,

but are designed to be weak, so that they can be overdriven by an external driver when data on the bus starts

flowing the opposite direction.

The output one shots detect rising or falling edges on the A or B ports. During a rising edge, the one shot turns

on the PMOS transistors (T1, T3) for a short duration, which speeds up the low-to-high transition. Similarly,

during a falling edge, the one shot turns on the NMOS transistors (T2, T4) for a short duration, which speeds up

the high-to-low transition. The typical output impedance during output transition is 70

Ω at V

50

Ω at V

Figure 1. Architecture of TXB0101 I/O Cell

the data I/Os of the TXB0101 must have drive strength of at least

±2 mA.

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