PCA9306

General description

The PCA9306 is a dual bidirectional I²C-bus and SMBus voltage-level translator with an enable (EN) input, and is operational from 1.0 V to 3.6 V (_Vref(1)) and 1.8 V to 5.5 V (V_bias(ref)(2)).

The PCA9306 allows bidirectional voltage translations between 1.0 V and 5 V without the use of a direction pin. The low ON-state resistance (R_on) of the switch allows connections to be made with minimal propagation delay. When EN is HIGH, the translator switch is on, and the SCL1 and SDA1 I/O are connected to the SCL2 and SDA2 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.

The PCA9306 is not a bus buffer like the PCA9509 or PCA9517A that provide both level translation and physically isolates the capacitance to either side of the bus when both sides are connected. The PCA9306 only isolates both sides when the device is disabled and provides voltage level translation when active.

The PCA9306 can also be used to run two buses, one at 400 kHz operating frequency and the other at 100 kHz operating frequency. If the two buses are operating at different frequencies, the 100 kHz bus must be isolated when the 400 kHz operation of the other bus is required. If the master is running at 400 kHz, the maximum system operating frequency may be less than 400 kHz because of the delays added by the translator.

As with the standard I²C-bus system, pull-up resistors are required to provide the logic HIGH levels on the translator's bus. The PCA9306 has a standard open-collector configuration of the I²C-bus. The size of these pull-up resistors depends on the system, but each side of the translator must have a pull-up resistor. The device is designed to work with Standard-mode, Fast-mode and Fast mode Plus I²C-bus devices in addition to SMBus devices. The maximum frequency is dependent on the RC time constant, but generally supports > 2 MHz.

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 VREF1. When the SDA1 port is HIGH, the SDA2 port is pulled to the drain pull-up supply voltage (V_pu(D)) by the pull-up 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 as the SDA1/SDA2 channel.

All channels have the same electrical characteristics and there is minimal deviation from one output to another in voltage or propagation delay. This is a benefit over discrete transistor voltage translation solutions, since the fabrication of the switch is symmetrical. The translator provides excellent ESD protection to lower voltage devices, and at the same time protects less ESD-resistant devices.

Features

• 2-bit bidirectional translator for SDA and SCL lines in mixed-mode I²C-bus applications
• Standard-mode, Fast-mode, and Fast-mode Plus I²C-bus and SMBus compatible
• Less than 1.5 ns maximum propagation delay to accommodate Standard-mode and Fast-mode I²C-bus devices and multiple masters
• Allows voltage level translation between:
  • 1.0 V V_ref(1) and 1.8 V, 2.5 V, 3.3 V or 5 V V_bias(ref)(2)
  • 1.2 V V_ref(1) and 1.8 V, 2.5 V, 3.3 V or 5 V V_bias(ref)(2)
  • 1.8 V V_ref(1) and 3.3 V or 5 V V_bias(ref)(2)
  • 2.5 V V_ref(1) and 5 V V_bias(ref)(2)
  • 3.3 V V_ref(1) and 5 V V_bias(ref)(2)
• Provides bidirectional voltage translation with no direction pin
• Low 3.5 Ohm ON-state connection between input and output ports provides less signal distortion
• Open-drain I²C-bus I/O ports (SCL1, SDA1, SCL2 and SDA2)
• 5 V tolerant I²C-bus I/O ports to support mixed-mode signal operation
• High-impedance SCL1, SDA1, SCL2 and SDA2 pins for EN = LOW
• Lock-up free operation
• Flow through pinout for ease of printed-circuit board trace routing
• ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115, and 1000 V CDM per JESD22-C101
• Packages offered: SO8, TSSOP8, VSSOP8, XQFN8

Products/packages

Quality/reliability/chemical content

Quality and reliability disclaimer

Pricing/ordering/availability

Applications

Related applications
Intelligent washing machine
Transceiver board

Block diagrams/pinning

Design support

Application Notes

AN10145; AN10145 Bi-directional low voltage translators (2004-08-11)

AN10216; I2C manual (2003-03-27)

AN10441; Level shifting techniques in I2C-bus design (2007-06-20)

Support Documents

design_con_2003_tecforum_i2c_bus_overview; DesignCon 2003 TecForum I 2 C Bus Overview (2003-01-27)

UM10206; I2C Demonstration Board 2005-1 Quick Start Guide (2006-06-13)

39340011_jp; I2C-bus specification (latest version) (2004-06-22)

UM10204; I2C-bus specification and user manual (2007-06-26)

web; IBIS and HSPICE Model ()

Parametrics/similar products

Similar products
PCA9306 links to the similar products page containing an overview of products that are similar in function or related to the type number(s) as listed on this page. The similar products page includes products from the same catalog tree(s), relevant selection guides and products from the same functional category.

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Disclaimers

• General product disclaimer
• Quality and reliability disclaimer