Vref_A

Vref_B

EN

A1

A2

B1

B2

LSF0108

200KΩ

Vcc

Vcc

Rpu

GPIO

GPIO

GPIO

GPIO

Vref(A) = 1.8V

Vpu= 5.0V

Rpu

Rpu

Vpu= 3.3V

GPIO

GPIO

1.8V

A3

A4

B3

B4

A5

A6

B5

B6

SCL

SDA

GPIO

GPIO

MDIO

MDC

SCL

SDA

MDIO

MDC

Rpu

Rpu

SW

SW

SW

SW

SW

SW

SW

SW

Vcc

15

LSF0101, LSF0102, LSF0108

www.ti.com

SDLS966H – DECEMBER 2013 – REVISED JUNE 2019

Product Folder Links: LSF0101 LSF0102 LSF0108

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Copyright © 2013–2019, Texas Instruments Incorporated

9.2.2 Mixed-Mode Voltage Translation

mixed-mode multi-voltage translation is shown in Figure 8. For additional details on multi-voltage translation, see

the Multi-voltage Translation with the LSF Family video.

With the Vref_B pulled up to 5V and Vref_A connected to 1.8V, all channels will be clamped to 1.8V at which

point a pullup can be used to define the high level voltage for a given channel.

•

Push-Pull Down Translation (5V to 1.8V): Channel 1 is an example of this setup. When B1 is 5V, A1 is

clamped to 1.8V, and when B1 is LOW, A1 is driven LOW through the switch.

•

Push-Pull Up Translation (1.8V to 5V): Channel 2 is an example of this setup. When A2 is 1.8V, the switch

is high impedance and the B2 channel is pulled up to 5V. When A2 is LOW, B2 is driven LOW through the

switch.

•

Push-Pull Down Translation (3.3V to 1.8V): Channels 3 and 4 are examples of this setup. When either B3

or B4 are driven to 3.3V, A3 or A4 are clamped to 1.8V, and when either B3 or B4 are LOW, A3 or A4 are

driven LOW through the switch.

•

Open-Drain Bidirectional Translation (3.3V

↔ 1.8V): Channels 5 through 8 are examples of this setup.

open-drain drivers.

Figure 8. Multi-Voltage Translation with the LSF0108