NCT5917W TR

NCT5917W Nuvoton Level translating I2C-bus/SMBus Repeater Date: Oct./08/2012 Revision: 1.0 NCT5917W NCT5917W Datasheet Revision History PAGES DATES VERSION MAIN CONTENTS 1 2012/01/17 0.1 Draft version. 2 2012/05/15 0.5 Preliminary version. 1.0 Public release 3 2012/10/08 -I- Release Date: Oct., 2012 Version: 1.0 NCT5917W Table of Content1. GENERAL DESCRIPTION ......................................................................................................... 1 2. FEATURES ................................................................................................................................. 1 3. BLOCK DIAGRAM ...................................................................................................................... 2 4. PIN CONFIGURATION ............................................................................................................... 2 4.1 5. FUNCTIONAL DESCRIPTION.................................................................................................... 4 5.1 6. Pin Description.............................................................................................................................3 Enable Pin....................................................................................................................................7 ELECTRICAL CHARACTERISTICS ........................................................................................... 8 6.1 Absolute Maximum Ratings ........................................................................................................8 6.2 DC Characteristics ......................................................................................................................8 6.3 AC CHARACTERISTICS ........................................................................................................ 11 6.4 Test Information........................................................................................................................ 12 7. ORDER INSTRUCTION............................................................................................................ 13 8. TOP MARKING SPECIFICATION ............................................................................................ 13 9. TAPING SPECIFICATION ........................................................................................................ 13 10. PACKAGE DRAWING AND DIMENSIONS .............................................................................. 14 - II - Release Date: Oct., 2012 Version: 1.0 NCT5917W 1. GENERAL DESCRIPTION The NCT5917W is a CMOS integrated circuit that provides bidirectional level shifting between higher voltage (2.7 V to 5.5 V) and low voltage (down to 0.9 V) up to 400KHz for SMBus TM applications. While retaining all the operating modes and features of the I2C-bus system during the level shifts, it 2 also permits extension of the I C-bus by providing bidirectional buffering for both the data (SDA) and the clock (SCL) lines, thus enabling two buses of 400pF. The SDA and SCL pins are over voltage 5V tolerant and are high-impedance when the NCT5917W is unpowered. The NCT5917W drivers are not enabled unless VCCB is above 2.5 V and VCCA is above 0.8 V. The EN pin can also be used to turn the drivers on and off under system control. Caution should be observed to only change the state of the enable pin when the bus is idle. The output pull-down on the B-side internal buffer LOW is set for approximately 0.5 V, while the input threshold of the internal buffer is set about 70 mV lower (0.43 V). When the B-side I/O is driven LOW internally, the LOW is not recognized as a LOW by the input. This prevents a lock-up condition from occurring. The output pull-down on the A-side drives a hard LOW and the input level is set at 0.3VCCA to accommodate the need for a lower LOW level in systems where the low voltage side supply voltage is as low as 0.9 V. The NCT5917W is packaged in MSOP-8 type. 2. FEATURES  2 channels, bidirectional voltage level from 0.9V to 5.5V and from 2.7V to 5.5V  A side operating supply voltage VCCA range from 0.9V to 5.5V  B side operating supply voltage VCCB range from 2.7V to 5.5V  Isolates Input/output sides  I C® Compatible System Management bus (SMBus ) operated up to 400 KHz  High active’s enable input  5V tolerant I C-bus and active high enable pin  high-impedance for I C-bus pins in power-off (VCCA