Miniature transceiver with voltage regulators and MCU support
The STKNX is a transceiver device for KNX TP communication. The small package and few external components enable the very compact KNX nodes design.
The simple interface to the μC allows easy replacement of physical layer discrete components implementations.
The STKNX device features two integrated voltage regulators for external use in the application: the selectable 3.3 V / 5 V - 20 mA linear regulator and the adjustable 1 V to 12 V - 150 mA high-efficiency DC/DC step down switching converter.
The integrated KNX bus power extractor supports bus current up to 30 mA to power external devices and the STKNX transceiver's own power needs, while limiting the bus current slew rate according to KNX specifications.
The STKNX assures the safe coupling to the bus and provides the bus monitoring warning for the loss of bus power.
Features
- Very thin fine pitch 4 x 4 mm VQFNPN24 package KNX certified, KNX TP1-256 supported
- Easy interface to μC
- Very small system solution
- Two integrated voltage regulators for external use in application
– Selectable 3.3 V / 5 V - 20 mA linear regulator
– Adjustable 1 V to 12 V - 150 mA highefficiency DC/DC step down switching converter - KNX bus power extractor supporting bus current up to 30 mA
- Adjustable KNX bus current slew rate dI/dt
- No crystal required
- Operating temperature range -40 °C to +85 °C
Application
KNX bus nodes in home and building control applications such as:
- Lighting and shutter control
- Security systems
- HVAC
- Monitoring and alarms
- Water control
- Energy management
- Smart metering
- Household appliance control
Key components
The STKNX evaluation and development kit (EVALKITSTKNX) includes all the components required to evaluate the performance of the miniature STKNX transceiver and to develop a KNX node on twisted pair medium in compliance with the TP1-256 standard. The system is controlled by an STM32F1 microcontroller hosting the KAIstack KNX protocol stack developed by TAPKO Technologies GmbH. Thanks to its Arduino and Morpho connectors, the kit lets developers connect existing STM32 expansion boards or to develop a custom board to create a complete prototype of a KNX device.
Diagram
