TI Adds Three Configurable 16-Bit I/O Expanders To Its Growing I2c Logic Portfolio

DALLAS (December 2, 2005) - Texas Instruments Incorporated (TI) (NYSE: TXN) today announced the release of three new 16-Bit Configurable I2C and SMBus I/O expanders. The PCA9555, PCA9535, and the PCA9539 16-bit I/O expanders provide general-purpose I/O expansion for most microprocessor families allowing designers to save the GPIOs on microprocessors for other important functions. These three I2C slave devices also utilize the industry preferred Nickel Palladium Gold (NiPdAu) RoHS compliant finish. (See: www.ti.com/i2c.)

As more features and processing requirements, such as LED control, hardware control monitors and humidity sensors in the computing space are added to applications, the limited numbers of GPIOs on microprocessors are becoming more valuable. By implementing these I/O Expanders, designers can utilize the microprocessor GPIOs for important functions and use the 16-Bit I/O expander for other duties, including system monitoring.

While all three devices have similar functionality, the PCA9539 is the premier part in this series of parts because it offers a /RESET input. In an I2C system, the /RESET input can be used to initialize the PCA9539 to its default state without de-powering it. This is useful in situations where the I2C bus has a glitch which prevents proper transmission of data between the microprocessor and slave devices (such as the PCA9539). Any incorrect data in the PCA9539 can then be eliminated through resetting it. Other slave devices without a /RESET input require their power supply to be lowered to 0V and then powered back up to Vcc for the slave device to return to its default state which can be inefficient and time consuming in the application.

Packaging, Pricing, and Availability

All three devices will be released in the ultra small QFN package making them ideal for space constrained applications. Currently, the PCA9555 is available in the industry standard SSOP, TSSOP, SOIC, and TVSOP packages. Budgetary pricing for the PCA9555DGVR (TVSOP) is set at $1.25 in quantities of 1,000. The PCA9535 is available in the industry standard SSOP, TSSOP, SOIC, and TVSOP packages. Budgetary pricing for the PCA9535DGVR (TVSOP) is set at $1.25 in quantities of 1,000. The PCA9539 is available in the industry standard SSOP, TSSOP, SOIC, and TVSOP packages. Budgetary pricing for the PCA9539DGVR (TVSOP) is set at $1.38 in quantities of 1,000.


These new devices join other I2C devices in the Standard Linear and Logic Must Have (www.ti.com/musthave) 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.

Contact Information

Sharon Hampton

Media Relations Manager

Texas Instruments Incorporated

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