AL1666

Document number: DS42417 Rev. 1 - 2

1 of 16

www.diodes.com

December 2019

© Diodes Incorporated

AL1666

HIGH PERFORMANCE DIMMABLE LED CONTROLLER

Description

The AL1666 is a high performance single stage Flyback and Buck-

boost controller, targeting dimmable LED lighting application. It is a

primary side regulation (PSR) controller which can provide accurate

Constant

Current

(CC)

regulation

without

opto-coupler

and

secondary control circuitry. It is operating at BCM mode which results

in good EMI and efficiency, and keeps high PF and low THD under

universal input voltage.

The AL1666 can support analog/PWM dimming modes. When a 0 to

2.4V DC signal is applied on ADIM pin, the device will operate in

analog dimming mode; when a digital signal is applied on PWMD pin

and the ADIM pin is connected with hundreds of nF capacitors, the

device will work at PWM-to-DC dimming mode. The dimming range is

1% to 100%.

The AL1666 has rich protection features. It integrates multiple

protections including Under Voltage Lock Out (UVLO), Output Over

Voltage Protection (OVP), Output Short Circuit Protection (OSP),

Over Current Protection (OCP), Winding Short Circuit, Secondary

Diode Short, Internal Thermal Fold-Back Protection (TFP) and Over

Temperature Protection (OTP).

The AL1666 is available in SO-8 (Standard) package.

Features



Primary Side Regulation without Opto-Coupler



Valley Switching for Low Switching Loss



Support Analog and PWM-to-DC Dimming



Analog/PWM-to-DC Dimming Range: 1% to 100%



Tight CS Reference Voltage 0.4V

±1.5%



High PF>0.9 and Low THD<20%



High Efficiency



Internal Protections



Under Voltage Lock Out (UVLO)



Output Over Voltage Protection (OVP)



Output Short Protection (OSP)



Over Current Protection (OCP)



Winding Short Circuit Protection



Secondary Diode Short Protection



Internal Thermal Fold-back Protection (TFP)



Over Temperature Protection (OTP)



Tight LED Current Variation Range



LED Current Line Regulation:



LED Current Load Regulation:

±2% Full Load to Half Load



Package: SO-8 (Standard)



Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)



Halogen and Anti

mony Free. “Green” Device (Note 3)



For automotive applications requiring specific change

control (i.e. parts qualified to AEC-Q100/101/200, PPAP

capable, and manufactured in IATF 16949 certified facilities),

please contact us or your local Diodes representative.

https://www.diodes.com/quality/product-definitions/

Pin Assignments

(Top View)

1

2

3

4

8

6

5

7

ADIM

PWMD

COMP

CS

GND

FB

OUT

VCC

SO-8 (Standard)

Applications



General LED Lighting Driver with Dimming Function



0 to 10V Dimming Luminaires



General Purpose Constant Current Source



Smart LED Lighting

Notes:

1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant.

2. See https://www.diodes.com/quality/lead-

free/ for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and

Lead-free.

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.