Maxim Introduces Offline LED Driver for Replacement Lamps
January 28, 2023
Maxim introduced the MAX16841 offline LED driver. Universal input (90VAC to 265VAC) allows the MAX16841 LED dimmer to be used in international dimmers, saving design time and cost. Leading (triac) and trailing edge (transistor) dimmers are used to provide flicker-free dimming from maximum light intensity to zero light intensity. Fixed frequency control optimizes the efficiency of low and high voltage AC lines. With a wide input range from 90VAC to 265VAC, the MAX16841 is a universal solution for dimmers in Japan, China, the United States, and Europe. This driver allows seamless replacement of incandescent and halogen lamps, thus avoiding compatibility issues with installed dimmers. The MAX16841 does not require an electrolytic capacitor to operate, further extending the life of the LED lamp. The elimination of capacitance also saves space and money. This LED driver is ideal for the upgrading of dimmable LED lamps and general-purpose LED lighting in industrial, commercial and residential lighting applications.
Dimming Problems for Upgrading Applications Dimmers increase or decrease the amount of light emitted by increasing or decreasing the amount of power supplied to the lamp. Now, the two most common voltage regulators are through leading (triac) and trailing (transistor) dimmers. Both types of dimmers adjust the power of the lamp by removing part of the AC waveform. As the name implies, the leading edge dimmer cuts the leading edge of the waveform after zero crossing, and the trailing edge dimmer cuts off the part before the waveform crosses zero. Leading edge dimmers are suitable for resistive or inductive loads, while trailing edge dimmers are suitable for resistive or capacitive loads.
In order to seamlessly replace traditional lighting, LED lights must be compatible with both front and rear edge dimmers. These dimmer designs are generally suitable for traditional halogen lamps and incandescent lamp resistive loads. However, the LED driver is non-linear and is not fully compatible with the purely resistive load of the dimmer. Therefore, when the LED lamp is connected to an existing electrical device with a dimmer, the LED lamp usually flickers and often dims, sometimes not even at all.
The MAX16841 solves this problem by using proprietary technology to control the input current of the lamp. By actively correcting the input current, this driver ensures flicker-free operation with most electronic transformers and dimmers. LED lamp designers can now design replacements that directly replace halogen lamps and incandescent lamps that can be dimmable to zero light.
Flexible Design Optimized for Efficiency in Any Operating Condition The MAX16841 can be designed for isolation (reverse-biased) and non-isolated (buck) configurations and is therefore not only suitable for high-voltage AC lines (220VAC to 230VAC) but also low-voltage AC lines (100VAC to 120VAC) Ideal choice. The fixed frequency control architecture uses the best conduction mode (DCM or CCM) based on the input voltage to increase efficiency. Since the switching regulator itself ensures sufficient holding current, the MAX16841 current control technique eliminates the need for a shunt to maintain the dimmer current, which improves dimming efficiency.
Universal input expands application area, reduces design time and costs - The MAX16841 is configurable as a universal input (90VAC to 265VAC) for flicker-free dimming in replacement applications worldwide. The MAX16841 also reduces inventory and saves design costs by eliminating the need for a separate LED driver to meet global voltage requirements.
Extend lamp life and save space The MAX16841 can be designed without electrolytic capacitors. Since electrolytic capacitors are usually the most vulnerable components of the driver circuit, this in turn extends the life of the LED lamp. If the existing design uses electrolytic capacitors, the MAX16841 can continue to maintain normal illumination even when these capacitors fail.
Eliminating electrolytic capacitors can also further reduce drive costs and size, making it suitable for small size applications. The MAX16841 is fully specified over the -40°C to +125°C temperature range. 8-pin SOIC package.
