SW

SW

LSF0102-Q1

8

6

2

7

3

4

5

EN

B1

B2

A2

A1

Vref_A

Vref_B

1

GND

9

LSF0102-Q1

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SDLS969 – MAY 2018

Product Folder Links: LSF0102-Q1

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8 Detailed Description

8.1 Overview

The LSF0102-Q1 device can be used in level translation applications for interfacing devices or systems operating

at different interface voltages. The LSF0102-Q1 device is ideal for use in applications where an open-drain driver

is connected to the data I/Os. With appropriate pull-up resistors and layout, the LSF0102-Q1 device can achieve

100 MHz. The LSF0102-Q1 can also be used in applications where a push-pull driver is connected to the data

I/Os.

8.2 Functional Block Diagrams

Figure 6. LSF0102-Q1 Functional Block Diagram

8.3 Feature Description

8.3.1 Auto Bidirectional Voltage Translation

The LSF0102-Q1 device is an auto bidirectional voltage level translator that operates from 0.95 to 4.5 V on

Vref_A and 1.8 to 5.5 V on Vref_B. This allows bidirectional voltage translation between 0.95 V and 5.5 V without

the need for a direction pin in open-drain or push-pull applications. The LSF0102-Q1 device supports level

translation applications with transmission speeds greater than 100 Mbps for open-drain systems using a 250-Ω

pullup resistor with a 30-pF capacitive load.

8.3.2 Output Enable

When EN is HIGH, the translator switch is on, and the An I/O is connected to the Bn I/O, respectively, allowing

bidirectional data flow between ports. When EN is LOW, the translator switch is off, and a high-impedance state

exists between ports. To enable the I/O pins, the EN input should be tied directly to Vref_B. To ensure the high-

impedance state during power-up or power-down, EN must be LOW. For additional details on how to use the

enable pin, see the Using the Enable Pin with the LSF Family video.

(1)

Table 1. Enable Function Table

FUNCTION

Tied directly to Vref_B

An = Bn

L

Hi-Z

8.3.3 Mixed-Mode Voltage Translation

The supply voltage (Vpu#) for each channel can be individually set up with a pull-up resistor. For example, CH1

can be used in up-translation mode (1.2 V

↔ 3.3 V) and CH2 in down-translation mode (2.5 V ↔ 1.8 V). For

additional details on how to use the LSF0102-Q1 for mixed-mode voltage translation, see the Multi-Voltage

Translation with the LSF Family video.