ON Semiconductor – Efficient new KNX transceivers boost power available for external loads


ON Semiconductor has introduced three new certified KNX twisted-pair transceivers for use in smart building- control systems, for which KNX is the most widely adopted standard. The new transceivers offer increased regulator current and boost overall efficiency by as much as 20% compared to existing solutions.

The NCN5110, NCN5121 and NCN5130 integrate two high-efficiency DC-DC converters and a 20V low drop-out regulator for powering external loads from the bus.

The NCN5121 and NCN5130 implement the complete KNX physical (PHY) and media- access (MAC) layers; the NCN5110 is an analogue-only bit transceiver to be used in combination with a microcontroller hosting the KNX MAC.

The NCN5121 is pin-to-pin compatible with ON Semiconductor’s NCN5120, but offers higher efficiency and regulator output.

The NCN5130 is capable of drawing up to 40mA from the KNX bus, giving designers greater flexibility to power devices such as an LCD panel or touchscreen from the communications network, or for driving relays at higher speeds.

The new devices also allow designers to specify lower external capacitance and inductance values, enabling the use of smaller supporting components. The NCN51xx devices are offered in a QFN-40 package and are specified for operation over the extended temperature range of -40°C to 105°C.


  • KNX communication speed of 9,600 baud
  • Supervision of KNX bus voltage
  • Control and monitoring of the DC-DC converters
  • Buffering of sent data frames
  • Optional auto-acknowledge
  • Operate with industry-standard 16MHz quartz crystal


  • Home appliances
  • Home/building automation
  • Smart lighting and switches
  • Ventilation and air-conditioning
  • Thermostats
  • Alarms and smoke detectors

The NCN51xx10GEVB evaluation board contains a KNX transceiver which handles the transmission and reception of data on the bus.

Orderable Part Numbers: NCN511010GEVB, NCN512110GEVB and NCN513010GEVB