pca9306 datasheet
Table Of Contents
- 1 Features
- 2 Applications
- 3 Description
- Table of Contents
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
- 6.1 Absolute Maximum Ratings
- 6.2 ESD Ratings
- 6.3 Recommended Operating Conditions
- 6.4 Thermal Information
- 6.5 Electrical Characteristics
- 6.6 Switching Characteristics AC Performance (Translating Down) (EN = 3.3 V)
- 6.7 Switching Characteristics AC Performance (Translating Down) (EN = 2.5 V)
- 6.8 Switching Characteristics AC Performance (Translating Up) (EN = 3.3 V)
- 6.9 Switching Characteristics AC Performance (Translating Up) (EN = 2.5 V)
- 6.10 Typical Characteristics
- 7 Parameter Measurement Information
- 8 Detailed Description
- 8.1 Overview
- 8.1.1 Definition of threshold voltage
- 8.1.2 Correct Device Set Up
- 8.1.3 Disconnecting a Slave from the Main I2C Bus Using the EN Pin
- 8.1.4 Supporting Remote Board Insertion to Backplane with PCA9306
- 8.1.5 Switch Configuration
- 8.1.6 Master on Side 1 or Side 2 of Device
- 8.1.7 LDO and PCA9306 Concerns
- 8.1.8 Current Limiting Resistance on VREF2
- 8.2 Functional Block Diagram
- 8.3 Feature Description
- 8.4 Device Functional Modes
- 8.1 Overview
- 9 Application and Implementation
- 10 Power Supply Recommendations
- 11 Layout
- 12 Device and Documentation Support
- 13 Mechanical, Packaging, and Orderable Information
1
2
3
4
5
6
7
8
SW
SW
V = 1.8 V
REF1
V = 3.3 V
DPU
I C Bus
Master
2
I C Bus
Device
2
V
REF1
V
REF2
EN
V
CC
V
CC
PCA9306
GND
GND
GND
SDA
SDA1
SDA2
200 kΩ
SCL1
SCL
SCL
SDA
SCL2
R
PU
R
PU
R
PU
R
PU
16
PCA9306
SCPS113M –OCTOBER 2004–REVISED APRIL 2019
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Product Folder Links: PCA9306
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9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
9.1.1 General Applications of I
2
C
As with the standard I
2
C system, pullup resistors are required to provide the logic-high levels on the translator
bus. The size of these pullup resistors depends on the system, but each side of the repeater must have a pullup
resistor. The device is designed to work with standard-mode and fast-mode I
2
C devices in addition to SMBus
devices. Standard-mode I
2
C devices only specify 3 mA in a generic I
2
C system where standard-mode devices
and multiple masters are possible. Under certain conditions, high termination currents can be used. When the
SDA1 or SDA2 port is low, the clamp is in the ON state, and a low-resistance connection exists between the
SDA1 and SDA2 ports. Assuming the higher voltage is on the SDA2 port when the SDA2 port is high, the voltage
on the SDA1 port is limited to the voltage set by V
REF1
. When the SDA1 port is high, the SDA2 port is pulled to
the pullup supply voltage of the drain (V
DPU
) by the pullup resistors. This functionality allows a seamless
translation between higher and lower voltages selected by the user, without the need for directional control. The
SCL1-SCL2 channel also functions in the same way as the SDA1-SDA2 channel.
9.2 Typical Application
Figure 16 and Figure 17 show how these pullup resistors are connected in a typical application, as well as two
options for connecting the EN pin.
Figure 16. Typical Application Circuit (Switch Always Enabled)