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SX1509BIULTRT

SX1509BIULTRT

Semtech Corporation
I/O Expander 16 I2C 400 kHz 28-QFN-UT (4x4)
Active18,408 in stock
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Overview

The SX1509BIULTRT is a highly integrated 16-channel I/O expander featuring a dedicated keypad scanning engine and an internal LED driver with PWM and breathing effects. It operates over a wide voltage range of 1.425V to 3.6V and includes built-in level shifting, making it ideal for interfacing low-voltage processors with peripherals of different logic levels.

Why Choose This Part

The SX1509BIULTRT stands out by offloading timing-critical tasks like PWM generation and keypad matrix scanning from the main processor. Its ability to perform level shifting on all 16 I/O pins simplifies BOM complexity in multi-rail digital systems.

Applications

User Interface Keypads
Utilizes the integrated 8x8 matrix keypad scanning engine to offload matrix scanning tasks from the host MCU, including automatic debouncing.
LED Status Indicators
Drives up to 16 LEDs with individual 256-step PWM intensity control and hardware-based 'breathing' or blinking timers to reduce I2C traffic.
Mixed-Voltage System Interfacing
Leverages the dual-bank voltage supply and 5.5V tolerant I/Os to act as a bidirectional level shifter between a 1.8V SoC and 3.3V or 5V peripherals.
Battery-Powered Handhelds
Designed for low-power operation with a 1uA sleep current and an ultra-low run current of 365uA at 2MHz.

Key Specifications

Features Keypad Controller, LED Output, POR
Interface I2C
Output Type Open Drain, Push-Pull
Mounting Type Surface Mount
Number of I/O 16
Package / Case 28-UFQFN Exposed Pad
Clock Frequency 400 kHz
Interrupt Output Yes
Voltage - Supply 1.425V ~ 3.6V
Operating Temperature -40degC ~ 85degC
Supplier Device Package 28-QFN-UT (4x4)
Current - Output Source/Sink 8mA, 15mA

Getting Started

Communicate with the device via the 400 kHz I2C interface using the NINT interrupt pin to notify the host of input changes or keypad events. For rapid prototyping, many engineers use the SparkFun SX1509 Breakout board which provides an accessible 0.1-inch pitch header for all 16 I/O pins.

Also Consider

TCA9555 TITexas Instruments - A standard 16-bit I2C I/O expander for applications that do not require specialized LED PWM or keypad scanning engines.
PCA9685 NXP Semiconductors - Consider this if your primary requirement is high-resolution 12-bit PWM control for up to 16 LED channels.
MCP23017 MCHPMicrochip Technology - A popular alternative with 16 I/Os and high-speed I2C (up to 1.7 MHz) available in multiple package types including SSOP and SPDIP.

Categories

Interface ICs > I/O Expanders