Semtech SX9306 Ultra-Low-Power SAR Proximity Sensor
Semtech SX9306 Ultra-Low-Power SAR Proximity Sensor is an ultra-low-power, capacitive proximity sensor with an On-Chip Smart Engine for human body detection and advanced SAR (Specific Absorption Rate) control. The on-chip smart engine can detect the permittivity of different surfaces, giving it the ability to accurately discriminate between inanimate objects or a human body.
The Semtech SX9306 Proximity Sensor is designed to allow designers of touchscreen devices, such as tablets and smartphones, to program these devices to reduce RF emission power when the devices are near a human body part. With higher RF-power devices and more extensive device usage, the SX9306 allows these manufacturers to proactively reduce SAR without affecting RF strength during normal use.
The SX9306 Proximity Sensor has four high-resolution capacitive sensor inputs with a 0.08 femto-farad (fF) sensing resolution. Each sensor also features a capacitance-offset compensation of up to 30 picofarads (pF). With its integrated RF shield, this device provides robust noise immunity and eliminates false triggers that commonly occur in these applications.
The SX9306 is available in two space-saving packages, a 3mm2, thin QFN package or a 1.63mm x 1.23mm WLCSP package.
Features
- 2.7V to 5.5V input supply voltage
- Up to 4 capacitive sensor inputs
- On-chip smart engine for human detection and advanced SAR control
- High-resolution capacitive sensing down to 0.08fF
- Capacitance offset compensation up to 30pF
- Configurable proximity detection (single/combined)
- Integrated high-performance RF shield for enhanced noise immunity
- Extremely low temperature drift for stable measurement
- Reduced VDD ripple susceptibility
- Active sensor guarding
- Automatic calibration
- Ultra-low power consumption
- 170µA in active mode
- 18µA in doze mode
- 2.5µA in sleep mode
- 400kHz I2C serial interface
- Four programmable I2C sub-addresses
- Input levels compatible with 1.8V host processors
- Open drain NIRQ interrupt pin
- Up to three reset sources including POR, Soft Reset, and NRST
- -40°C to +85°C operating temperature range
- Package options
- 1.63mm x 1.23mm WLCSP
- 3mm2 thin QFN
- QFN version pin-to-pin compatible with SX9300/SX9500
- Lead-free, Halogen-free, and RoHS/WEEE compliant
Applications
- SAR compliant systems
- Tablets/phablets
- Smartphones
- Wearable devices
- Touchscreen panels
Typical Application Circuit
Evaluation Kit
Semtech SX9306EVKA Evaluation Kit is designed to demonstrate the functionality of the Semtech SX9306 Ultra-Low Power SAR Proximity Sensor and facilitate faster project development. The included easy-to-use Windows-based GUI software allows monitoring of touch and proximity detection, displays raw registers, cap sensing data, and more.