TCAL9539RTWRQ1

• 16-Bit I/O Expander Adding Sixteen Configurable Pins Over a Two-Wire Bus
• I2C and SMBus Interface per the Product Title
• Interrupt output, Reset Input and Agile I/O Configuration per the Product Title
• 24-Pin Surface-Mount WQFN, 4mm by 4mm, 800um Height
• Automotive -40 to 125 Degrees C Range per the Product Title
• RoHS Compliant and Listed by Texas Instruments in Active Production

The Texas Instruments TCAL9539RTWRQ1 is an automotive-qualified 16-bit low-voltage I/O expander with an I2C and SMBus interface, offering interrupt, reset and agile I/O configuration as described in its product title. An I/O expander adds general-purpose input and output pins to a system over a two-wire bus, which is how designers gain port count without moving to a larger microcontroller. The TCAL9539RTWRQ1 is housed in a 24-pin surface-mount WQFN measuring 4mm by 4mm with an 800um height. It is RoHS compliant and Texas Instruments lists it in active production; the product title specifies a -40 to 125 degrees C automotive temperature range.

I/O expanders solve a routing and pin-count problem: a controller that has run out of GPIO can add sixteen more pins at the far end of a two-wire bus, keeping the connections short to the switches, LEDs and control lines they serve rather than running long traces back to the processor. In vehicles the TCAL9539RTWRQ1 is used for button and switch panel scanning, LED and backlight control, discrete enable and reset lines to peripheral modules, and status monitoring in body control, infotainment and cluster electronics. The interrupt output is what makes this practical, letting the expander signal a pin change instead of forcing the host to poll the bus. Buyers are automotive tier-one suppliers and industrial equipment manufacturers requiring a -40 to 125 degrees C qualified part.