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TI Continues Growth in the I2C™ Market with the Addition of Three Four-Channel I2C and SMBus™ Multiplexers and Switches

Feb 17, 2006

DALLAS (Feb. 17, 2006) - Texas Instruments Incorporated (TI) (NYSE: TXN) today announced the release of three new four-bit bidirectional translating (level-shifting) I2C and SMBus multiplexers and switches. The PCA9544A, PCA9545A and PCA9546A support voltage level translation between 2.5V, 3.3V and 5V buses, which is essential in mixed voltage I2C systems. (See: www.ti.com/i2c.)

As the popular I2C two-wire communication bus standard continues to be adopted in many system applications, including computing and portable electronics, it is important to have I2C- and SMBus-compatible multiplexers and switches that can support the mixed voltage I2C systems. Controlled via the I2C bus, TI's new four-channel bidirectional switches support voltage interface between 2.5V, 3.3V and 5V buses. Each upstream channel (SCL/SDA) fans out to four downstream channels where each individual SCn/SDn channel or combination of channels can be selected through the contents of the programmable control register. This type of internal architecture allows designers to isolate a section of the I2C bus through I2C software, which provides pin savings in the processor. These free pins on the processor can now be used for other functions. These I2C switches and multiplexers can also be used to resolve I2C address conflicts. These devices also support standard- and fast-mode speeds.
Of these three devices, the PCA9545A has the highest feature set. All four channels in this device can be selected at the same time, providing for more design flexibility. This device offers an interrupt output and reset input along with a low on-state resistance (Ron=10 ohms), improving signal degradation between the input and output channels. All three devices are useful for a range of applications, including system monitoring in both telecom and computing.

Additional Multiplexer Features

  • Low RON switches (10 ohm typically) 
  • Vcc range of 2.3V to 5.5V 
  • Interface with 400 kbit/s Fast I2C Bus 
  • Low power consumption 
  • Ultra-small QFN package 
  • All packages are lead(Pb)-free (NiPdAu finish)

Packaging, Pricing, and Availability

All three devices are available now with free samples support. The PCA9544A, PCA9545A and PCA9546A are available in the industry standard 20-pin SSOP, TSSOP, SOIC, and TVSOP packages along with the space-saving Quad Flat Pack (QFN) and Ball Grid Array (BGA) package options. Budgetary pricing for the PCA9544ADGVR and PCA9545ADGVR (TVSOP) is set at $2.75 in quantities of 1,000. Budgetary pricing for the PCA9546ADGVR (TVSOP) is set at $1.74 in quantities of 1,000.

These new devices join other I2C devices in the Standard Linear and Logic Must Have (


) product offerings. TI's Must Have products are a select group of Standard Linear and Logic products that provide a focused priority for the customer.