G3401 Global Mixed-mode Technology Dual Bidirectional I2C Bus and SMBus VoltageLevel Translator is low, the translator switch is off, and a high-impedance exists between ports. Features 2-Bit Bidirectional Translator for SDA and SCL Lines in Mix-Mode I2C Applications 2 I C and SMBus Compatible Less than 1.5ns Maximum Propagation Delay to Accommodate Standard-Mode and Fast-Model I2C Devices and Multiple Masters Allows Voltage-Level Translator Between 1.2V VREF1 and 2.5V, 3.3V, 5V VREF2 1.8V VREF1 and 3.3V, 5V VREF2 3.3V VREF1 and 5V VREF2 Provides Bidirectional Voltage Translation without Direction Pin Low 3.5Ω ON-State Connection Between Input and Output Ports Provides Less Signal Distortion 2 Open-Drain I C I/O Ports 2 5V Tolerant I C I/O Ports to Support Mixed Mode Signal Operation High Impedance SCL1,SDA1,SCL2 and SDA2 Pins for EN=Low Lock-up-Free Operation for Isolation When EN=Low 2 In I C applications, the bus capacitance limit of 400pF restricts the number of devices and bus length. The system designer could isolate two halves of a bus by using the G3401; thus, more I2C devices or longer trace length can be accommodated. 2 In standard I C system, pull-up resistors are required to provide the logic high levels on the translator’s bus. The size of these pull-up resistors depends on the system, but each side of the repeater must have a pull-up resistor. The G3401 is designed to work with standard-mode and fast-mode I2C devices. Standard mode I2C devices only specify 3mA in a generic I2C 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 VREF1. When the SDA1 is high the SDA2 port is pulled up to the drain pull-up supply voltage (VDPU) by pull-up resistors. This function allows a seamless translation between higher and lower voltages selected by the user, without any directional control. The SCL1/SCL2 channel works like the SDA1/SDA2 channel. General Description The G3401 is a dual bidirectional I2C and SMBUS voltage-level translator with an enable (EN) input, and is operational from 1.2V to 3.3V VREF1 and 2.5V to 5.5V VREF2 . It allows bidirectional voltage translations between 1.2V and 5V, without use of directional pin. The low ON-state resistance (rON) of the switch ensures the connections to be with minimal propagation delay. When EN is high, the translator switch is ON, and the SCL1 I/O and SDA1 I/O are connected to the SCL2 and SDA2 I/O, respectively, allowing bidirectional data flow between ports. When EN 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 translation solutions, since the fabrication of the switch is symmetrical. Ordering Information ORDER NUMBER MARKING TEMP. RANGE PACKAGE (Green) REMARK G3401V11U 3401 -40°C to 85°C VSSOP-8 OBSOLETE G3401KC1G G3401A91G 3401 -40°C to 85°C TDFN3X2-8 3401 -40°C to 85°C ADFN3X2-8 34 G3401A71U -40°C to 85°C AQFN1.5X1.5-8 1x Note: V1: VSSOP-8 KC: TDFN3X2-8 A9: ADFN3X2-8 A7: AQFN1.5X1.5-8 1: Bonding Code U & G: Tape & reel Pin Configuration 8 EN 2 7 VREF2 SCL1 3 6 SCL2 SDA1 4 5 SDA2 1 VREF2 2 SCL2 3 SDA2 4 Thermal Pad 8 GND 7 VREF1 6 5 EN GND 1 8 EN VREF1 2 7 VREF2 SCL1 SCL1 3 6 SCL2 SDA1 SDA1 4 5 SDA2 TDFN3X2-8 ADFN3X2-8 Note: Recommend connecting the Thermal Pad to the Ground for excellent power dissipation. 8 1 EN G3401 7 VREF1 2 6 SCL1 3 5 SDA1 VREF2 1 SCL2 SDA2 4 GND VREF1 VSSOP-8 G3401 G3401 G3401 VSS AQFN1.5X1.5-8 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.6 May 31, 2013 1