TCA9509

SCPS225B

– AUGUST 2011 – REVISED JANUARY 2012

www.ti.com

ORDERING INFORMATION

ORDERABLE PART

TOP-SIDE MARKING

NUMBERS

–40°C to 85°C

TCA9509RVHR

RVH - QFN

Tape and reel

7K

–40°C to 85°C

TCA9509DGKR

DGK - MSOP

Tape and reel

7KQ

(1)

Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.

(2)

For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI

website at www.ti.com.

DESCRIPTION/ORDERING INFORMATION (CONTINUED)

The bus port B drivers are compliant with SMBus I/O levels, while the A side uses a current sensing mechanism

to detect the input or output LOW signal which prevents bus lock-up. The A side uses a 1 mA current source for

pull-up and a 200

Ω pull-down driver. This results in a LOW on the A side accommodating smaller voltage

swings. The output pull-down on the A side internal buffer LOW is set for approximately 0.2 V, while the input

threshold of the internal buffer is set about 50 mV lower than that of the output voltage LOW. When the A 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 B side drives a hard LOW and the input level is set at 0.3 of SMBus

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 EN pin when the bus is idle.

an

2

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© 2011–2012, Texas Instruments Incorporated

Product Folder Link(s): TCA9509