LED Driver with Integrated MOSFET for MR16 and Other 12V AC Input Lamps

Unique Solution Allows MR16 LED Lamps to Be Compatible with Most Electronic Transformers and is Dimmable Flicker-Free

Please check latest availability status for a specific part variant.


The MAX16840 is an LED driver IC for lighting applications. It includes all the necessary features to design low-component-count LED drivers for 12V AC and 24V AC input (e.g., MR16) light bulbs. A proprietary input-current control scheme allows LED lamps based on this device to be compatible with electronic transformers, and dimmable with standard trailing-edge dimmers (where electronic transformers are present).

The IC can be used in buck, boost, and buck-boost topologies and features. It has an integrated 0.2Ω (max), 48V switching MOSFET.

The IC uses constant-frequency average current-mode control. It senses the input current through the voltage at the FB pin, and regulates its average. An input pin (REFI) allows the setting of the input-current level. When the voltage at this pin is set below a certain threshold, the input current is proportional to this voltage, while when that voltage is beyond the threshold, the input current is set at a fixed, predefined level. This nonlinear behavior of REFI allows its use to achieve thermal foldback, by connecting it to an NTC resistor.

The IC also features an internal overvoltage protection on the IN pin to protect the internal switching MOSFET from damage if the LED string is open or if the voltage on the LED string is too high.

The IC has a separate EXT pin that can be used to guarantee that there is a kick-start of current at turn-on for low-input voltages for proper operation with electronic transformers. EXT drives an external npn transistor. Once the UVLO threshold of 5.5V is crossed on IN, EXT is pulled to ground and the external npn transistor is turned off.

The IC is available in a 3mm x 3mm, 10-pin TDFN power package, and is rated over the -40°C to +125°C operating temperature range.

MAX16840: Typical Operating Circuit MAX16840: Typical Operating Circuit Enlarge+

Key Features

  • Cost-Effective Solution for MR16 and Other SSL Applications
    • Proprietary Input Current-Control Scheme to Achieve Electronic Transformer Compatibility and Dimmability
    • Buck, Boost, SEPIC, and Buck-Boost Topologies
    • Analog Dimming
  • Minimal Component Count Saves Cost and Space
    • Integrated 0.2Ω (max) 48V Switching MOSFET
  • Protection Features and Wide Operating Temperature Range Improves Reliability
    • Thermal-Foldback Protection
    • Output Overvoltage Protection
    • Internal Overtemperature Protection
    • Available in a 10-Pin Thermally Enhanced TDFN Package
    • Operation Over -40°C to +125°C Temperature Range


  • MR16 and Other 12V AC or DC Input LED Lighting Applications
Part NumberRegulation TopologyMax. No. of LEDsLED ChannelsLED ConfigurationILED per Channel
Dimming ControlVCURR_SENSE
LED String Volt.
Oper. Freq.
maxminmaxmaxmaxSee Notes
MAX16840 Inductor Based111Series1Analog200126.548248300
$2.20 @1k
See All LED Drivers (79)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX16840EVKIT: Evaluation Kit for the MAX16840
MAX16840LEVKIT: Evaluation Kit for the MAX16840
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >


Related Resources

Integrated, 6-Channel High-Brightness LED Driver with Very Wide PWM Dimming Ratio and Phase Shifting for Automotive Displays

  • Robust with Respect to EMC and Automotive Battery Transients
  • Spread-Spectrum Mode Reduces Emission at the Switching Frequency and its Harmonics
  • Phase-Shift Dimming of LED Strings

Automotive Synchronous High Voltage LED Controller

  • Integration Minimizes BOM and Cost
  • Simple to Optimize for Efficiency, Board Space, and Input Operating Range
  • Protection Features Increase System Reliability