ZHCSQD8C July 2007 – April 2022 PCA9306-Q1
PRODUCTION DATA
- 1 特性
- 2 应用
- 3 说明
- 4 Revision History
- 5 说明（续）
- 6 Pin Configuration and Functions
-
7 Specifications
- 7.1 Absolute Maximum Ratings
- 7.2 ESD Ratings
- 7.3 Recommended Operating Conditions
- 7.4 Thermal Information
- 7.5 Electrical Characteristics
- 7.6 Switching Characteristics: Translating Down, VIH = 3.3 V
- 7.7 Switching Characteristics: Translating Down, VIH = 2.5 V
- 7.8 Switching Characteristics: Translating Up, VIH = 2.3 V
- 7.9 Switching Characteristics: Translating Up, VIH = 1.5 V
- 7.10 Typical Characteristics
- 8 Parameter Measurement Information
-
9 Detailed Description
- 9.1
Overview
- 9.1.1 Definition of threshold voltage
- 9.1.2 Correct Device Set Up
- 9.1.3 Disconnecting a Target from the Main I2C Bus Using the EN Pin
- 9.1.4 Supporting Remote Board Insertion to Backplane with PCA9306-Q1
- 9.1.5 Switch Configuration
- 9.1.6 Controller on Side 1 or Side 2 of Device
- 9.1.7 LDO and PCA9306-Q1 Concerns
- 9.1.8 Current Limiting Resistance on VREF2
- 9.2 Functional Block Diagram
- 9.3 Feature Description
- 9.4 Device Functional Modes
- 9.1
Overview
- 10Application and Implementation
- 11Power Supply Recommendations
- 12Layout
- 13Device and Documentation Support
- 14Mechanical, Packaging, and Orderable Information
9.1.5 Switch Configuration
PCA9306-Q1 has the capability of being used with its VREF1 voltage equal to VREF2. This essentially turns the device from a translator to a device which can be used as a switch, and in some situations this can be useful. The switch configuration is shown in Figure 9-5 and translation mode is shown in Figure 9-6.
Figure 9-5 Switch Configuration
Figure 9-6 Translation ConfigurationWhen PCA9306-Q1 is in the switch configuration (VREF1 = VREF2), the propagation delays are different compared to the translator configuration. Taking a look at the propagation delays, if the pull up resistance and capacitance on both sides of the bus are equal, then in switch mode the PCA9306-Q1 has the same propagation delay from side one to two and side two to one. The propagation delays become lower when VCC1/VCC2 is larger. For example, the propagation delay at 1.8 V is longer than at 5 V in the switching configuration. When PCA9306-Q1 is in translation mode, side one propagate lows to side two faster than side two can propagate lows to side 1. This time difference increases as the difference between VCC2 and VCC1 becomes larger.