Four-channel bidirectional level shifter with auto-direction sensing
The Texas Instruments TXS0104EYZTR is a 4-channel bidirectional voltage-level translator that uses auto-direction sensing to eliminate the direction-control pin, simplifying board layout for open-drain and push-pull buses like I2C, SMBus, and 1-Wire. It supports a data rate of 24 Mbps, which is adequate for standard serial protocols but not for high-speed interfaces like SPI above 10 MHz or SDIO. Housed in a 12-DSBGA package measuring 1.9 x 1.4 mm, it saves significant board area but demands a well-controlled solder-paste stencil and reflow profile to avoid opens on the small bumps.
Supply-rail sequencing and decoupling
The A-side supply (VCCA) must be powered before or simultaneously with the B-side supply (VCCB) to avoid latch-up or undefined output states during power-up. Each supply pin needs a 0.1 µF ceramic capacitor placed as close to the ball as possible; the DSBGA's fine pitch makes via-in-pad or microvia routing necessary to keep the loop small.