High Efficiency PWM Buck LED Driver Controller


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The RT8458 is a PWM controller with an integrated high side floating gate driver. It is used for step down converters by well controlling the external MOSFET and regulating a constant output current. The output duty cycle of the RT8458 can be up to 100% for wider input voltage application, such as E27 and PAR30 off-line LED lighting products.

The RT8458 also features a 47kHz fixed frequency oscillator, an internal -178mV precision reference, and a PWM comparator with latching logic. The accurate output LED current is achieved by an averaging current feedback loop and the LED current dimming can be easily controlled via the ACTL pin. The RT8458 also has multiple features to protect the controller from fault conditions, including Under Voltage Lockout (UVLO), Over Current Protection (OCP) and Over Voltage Protection (OVP). Additionally, to ensure the system reliability, the RT8458 is built with the thermal protection function.

The RT8458 is housed in a TSOT-23-6 package. Thus, the components in the whole LED driver system can be made very compact.


  • E27, PAR30, Offline LED Lights
Key Spec.
Status NRND
Recommended Alternative  RT8458A
Vin (min) (V) 17
Vin (max) (V) 32
Topology Buck
Current Sense Threshold (mV) 178
Dimming Control Analog
Features OCP;OVP
Package Type TSOT-26
  • Low Cost and Efficient Buck Converter Solution
  • Universal Input Voltage Range with Off-Line Topology
  • Programmable Constant LED Current
  • Dimmable LED Current by ACTL
  • Output LED String Open Protection
  • Output LED String Short Protection
  • Output LED String Over Current Protection
  • Built-in Thermal Protection
  • TSOT-23-6 Package
  • RoHS Compliant and Halogen Free
Title Last Update ShareDownload
High Efficiency PWM Buck LED Driver Controller 2015/05/19
Technical Documents
TitleLast UpdateShareDownload
Minimizing Light Flicker in LED Lighting Applications2018/08/15
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT8458GJ6TSOT-263000 Not available Buy from Distributor