High Efficiency PWM Buck LED Driver Controller


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The RT8458A is a PWM controller with an integrated high side 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 RT8458A can be up to 100% for wider input voltage application, such as E27 and PAR30 off-line LED lighting products.

The RT8458A also features a 47kHz fixed frequency oscillator, an internal -220mV 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 RT8458A 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 RT8458A is built with the thermal protection function.

The RT8458A is housed in a TSOT-23-6 package. Thus, the components in the whole LED driver system can be made very compact.


Key Spec.
Status Active
Vin (min) (V) 17
Vin (max) (V) 31
Topology Buck
Current Sense Threshold (mV) 220
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
TitleLast UpdateShareDownload
High Efficiency PWM Buck LED Driver Controller2012/03/15
Title Last Update ShareDownload
High Efficiency PWM Buck LED Driver Controller 2015/05/19
Technical Documents
TitleLast UpdateShareDownload
Power Solutions for LED Lighting Applications2018/11/22
Minimizing Light Flicker in LED Lighting Applications2018/08/15
Design Tool
TitleLast UpdateShare
RT8458A DC/CC Design tool (CCM)2020/02/05
RT8458A Design tool2020/02/05
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT8458AGJ6TSOT-263000 Request Buy from Distributor