8 Detailed Description

8.1 Overview

device and several slave devices. The master, or processor, controls the bus, specifically the serial clock (SCL)

line. Data is transferred between the master and slave through a serial data (SDA) line. This data can be

transferred in four speeds: standard mode (0 to 100 kbps), fast mode (0 to 400 kbps), fast-mode plus (0 to 1

Mbps), and high-speed mode (0 to 3.4 Mbps).

devices to share the bus. When a specific device is ready to communicate on the bus, it can take control pulling

the lines low accordingly in order to transmit data. A standard digital isolator or optocoupler is designed to

bidirectional bus into two unidirectional signal paths. The ISO164x devices internally handles the separation and

partitioning of the transmit and receive signals, integrating the external circuitry needed and provide the open

collector signals. They provide high electromagnetic immunity and low emissions at low power consumption.

Each isolation channel has a logic input and output buffer separated by TI's double capacitive silicon dioxide

(SiO2) insulation barrier. When used in conjunction with isolated power supplies, these devices block high

voltages, isolate grounds, and prevent noise currents from entering the local ground and interfering with or

damaging sensitive circuitry.

8.2 Functional Block Diagrams

SDA2

SCL1

SCL2

GND2

GND1

VCC2

VCC1

SDA1

VREF

VREF

Figure 8-1. ISO1640 Block Diagram

8.3 Feature Description

features listed in Table 8-1.

Table 8-1. Features List

PART NUMBER

CHANNEL DIRECTION

RATED ISOLATION(1)

MAXIMUM FREQUENCY

ISO1640

Bidirectional (SCL)

Bidirectional (SDA)

1.7 MHz

(1)

See for detailed Isolation specifications.

ISO1640

SLLSFC2 – OCTOBER 2020

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