UNIVERSAL, 500V BUCK LED DRIVER
The AL1678-20B/10B/08B is a universal AC input (85 to 277 VAC),
high efficiency and high accuracy Buck LED driver. The AL1678-
20B/10B/08B topology provides accurate constant current over line
and load regulation with tight tolerance ±3%, operating at boundary
conduction mode (BCM) to ease in EMI/EMC qualification and testing
to meet the latest regulatory laws.
The AL1678-20B/10B/08B single Buck stage system works with a
single winding inductor and High voltage MOSFET included,
therefore, can use fewer external components and create a low bill of
material (BOM) cost solution. The AL1678-20B/10B/08B has rich
protection features to enhance the system safety and reliability. It has
thermal fold back function, which can reduce the output current when
the driver’s temperature is higher than the setting value.
The AL1678-20B/10B/08B is available in SO-7 package.
> 90% Efficiency
Valley Switching to Achieve Low Switching Loss
Universal 85 to 277 VAC Input Range
Internal MOSFET up to 500V
Tight Current Sense Tolerance: ±3%
Low Start-up Current: 170µA
Low Operation Current: 100µA (Static)
Single Winding Inductor
Under Voltage Lock Out (UVLO)
Leading-edge Blanking (LEB)
Output Open/Short Protection
Open-load and Reload Detection
Thermal Fold-back Function
Over Temperature Protection (OTP)
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Retrofit LED Lamps
High Voltage DC-DC LED Driver
General Purpose Constant Current Source
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
Typical Applications Circuit
1 OUT Drain 7
4 GND CS 5
U1 AL1678-20B/10B/08B R5
Document number: DS37637 Rev. 1 - 2
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