ver: 0.6 may 31, 2013 tel: 886-3-5788833 http://www.gmt.com.tw 1 G3401 global mixed-mode technology dual bidirectional i 2 c bus and smbus voltage- level translator features ? 2-bit bidirectional translator for sda and scl lines in mix-mode i 2 c applications ? i 2 c and smbus compatible ? less than 1.5ns maximum propagation delay to accommodate standard-mode and fast-model i 2 c devices and multiple masters ? allows voltage-level translator between ? 1.2v v ref1 and 2.5v, 3.3v, 5v v ref2 ? 1.8v v ref1 and 3.3v, 5v v ref2 ? 3.3v v ref1 and 5v v ref2 ? provides bidirectional voltage translation without direction pin ? low 3.5 on-state connection between input and output ports provides less signal distortion ? open-drain i 2 c i/o ports ? 5v tolerant i 2 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 general description the G3401 is a dual bidirectional i 2 c and smbus volt- age-level translator with an enable (en) input, and is op- erational from 1.2v to 3.3v v ref1 and 2.5v to 5.5v v ref2 . it allows bidirectional voltage translations between 1.2v and 5v, without use of directi onal pin. the low on-state resistance (r on ) of the switch ensur es 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 is low, the translator switch is off, and a high-impedance exists between ports. in i 2 c applications, the bus c apacitance limit of 400pf restricts the number of devic es and bus length. the sys- tem designer could isolate two halves of a bus by using the G3401; thus, more i 2 c devices or longer trace length can be accommodated. in standard i 2 c system, pull-up resistors are required to provide the logic high levels on the translator?s bus. the size of these pull-up resist ors depends on the system, but each side of the repeater mu st have a pull-up resistor. the G3401 is designed to work with standard-mode and fast-mode i 2 c devices. standard mode i 2 c devices only specify 3ma in a generic i 2 c system where standard mode devices and multiple ma sters are possible. under certain conditions, high termi nation currents can be used. when the sda1 or sda2 port is low, the clamp is in the on state, and a low resist ance 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 lim ited to the voltage set by v ref1 . when the sda1 is high the sda2 port is pulled up to the drain pull-up supply voltage (v dpu ) by pull-up resis- tors. this function allows a seamless translation between higher and lower voltages sele cted by the user, without any directional control. the scl1/scl2 channel works like the sda1/sda2 channel. all channels have the same elec trical characteristics, and there is minimal deviation fr om one output to another in voltage or propagation delay. th is is a benefit over dis- crete translation solutions, si nce the fabric ation 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 3401 -40 c to 85 c tdfn3x2-8 G3401a91g 3401 -40 c to 85 c adfn3x2-8 G3401a71u 34 1x -40 c to 85 c aqfn1.5x1.5-8 note: v1: vssop-8 kc: tdfn3x2-8 a9: adfn3x2-8 a7: aqfn1.5x1.5-8 1: bonding code u & g: tape & reel pin configuration vssop-8 1 2 3 4 5 6 7 8 G3401 en vref2 scl2 sda2 gnd vref1 scl1 sda1 tdfn3x2-8 1 2 3 4 5 6 7 8 G3401 thermal pad en vref2 scl2 sda2 gnd vref1 scl1 sda1 note: recommend connecting the thermal pad to the ground for excellent power dissipation. adfn3x2-8 1 2 3 4 5 6 7 8 G3401 gnd vref1 scl1 sda1 en vref2 scl2 sda2 4 8 3 2 1 5 6 7 aqfn1.5x1.5-8 vss vref2 scl2 sda2 en vref1 scl1 sda1 G3401 vssop-8 1 2 3 4 5 6 7 8 G3401 en vref2 scl2 sda2 gnd vref1 scl1 sda1 tdfn3x2-8 1 2 3 4 5 6 7 8 G3401 thermal pad en vref2 scl2 sda2 gnd vref1 scl1 sda1 note: recommend connecting the thermal pad to the ground for excellent power dissipation. adfn3x2-8 1 2 3 4 5 6 7 8 G3401 gnd vref1 scl1 sda1 en vref2 scl2 sda2 4 8 3 2 1 5 6 7 aqfn1.5x1.5-8 vss vref2 scl2 sda2 en vref1 scl1 sda1 G3401
|
