SX1508BIULTRT

Overview

The SX1508BIULTRT is an ultra-low voltage General Purpose Input/Output (GPIO) expander manufactured by Semtech Corporation. It features 8 bidirectional I/O channels and operates with a main supply voltage (VDDM) ranging from 1.425 V to 3.6 V, while dual independent I/O banks (VCC1, VCC2) support voltages between 1.2 V and 3.6 V. The device communicates via a standard 400 kHz I²C interface and includes an internal 2 MHz oscillator. Key electrical specifications include up to 15 mA output sink current per pin, 2 kV HBM ESD protection, and typical operating currents of 175 µA at 3.6 V. It is housed in a QFN-UT-20 package.

Feature Summary

• Integrated LED driver supporting intensity control via 256-step PWM, blinking, and breathing functions.
• On-chip keypad scanning engine capable of monitoring matrices up to 8x8 without host intervention.
• Dual independent I/O rails enabling direct level shifting between components operating at different voltage levels.
• Mask-programmable interrupt generation based on rising or falling edges with dedicated NINT output.

Applications

• Low power handheld battery-powered equipment
• Cell phones and PDAs
• MP3 players and digital cameras
• Notebooks and GPS units

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to ensure correct packaging and tape-and-reel specifications. Confirm that the component meets RoHS and WEEE compliance requirements for your target market. Cross-reference the datasheet revision date to ensure compatibility with your design specifications.

Selection Notes

Select this component when system design requires expansion of GPIO ports via I²C with minimal footprint. It is suitable for applications needing integrated LED driving or keypad scanning capabilities. Ensure the host controller supports the required I²C addressing modes and that the voltage levels of connected peripherals fall within the specified 1.2 V to 3.6 V range for the I/O banks.

Part Context

This part belongs to the SX1508B/SX1509B series of world’s lowest voltage level-shifting GPIOs. The SX1508B variant specifically provides 8 channels, whereas the SX1509B offers 16 channels. Both share similar architectural features including the LED driver and keypad engine, differing primarily in channel count and package size (QFN-UT-20 vs. QFN-UT-28).

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided source material. Consult the manufacturer's official documentation for potential cross-references or updated revisions.