Document
NOT RECOMMENDED FOR NEW DESIGN NO ALTERNATIVE PART
AL1672
SINGLE STAGE DIMMABLE BUCK CONVERTER WITH 600V/4A MOSFET
Description
The AL1672 is a high performance single stage Buck convertor, targeting dimmable LED lighting application. It is operating at BCM mode which results in good EMI and efficiency.
The AL1672 can support multiple dimming modes. When a 0.3~2.4V DC signal is applied on APWM pin, the device will operate in analog dimming mode. When a digital signal is applied on APWM pin, the device works at PWM dimming mode.
The AL1672 features low start-up current and low operation current. It integrates multiple protections including over voltage, short circuit, over current and over temperature protection. It also integrates 600V/4A high voltage MOSFET.
The AL1672 is available in SO-8EP package.
Pin Assignments
(Top View)
CS 1 GND 2
EP DRAIN 3 DRAIN 4
SO-8EP
8 COMP 7 APWM 6 FB 5 VCC
Features
Applications
• Valley Switching for Low Switching Loss • Low Start-Up Current • High PF and Low THD • High Efficiency • Tight LED Current Variation Range • Tight Output Open Voltage Variation Range • Integrates 600V/4A MOSFET • Support Both PWM Dimming and Analog Dimming
PWM Dimming Range:3% to 100% at 1kHz PWM Frequency
Analog Dimming and PWM-to-DC Dimming Range:18% to 100%
• Internal Protections Under Voltage Lock Out (UVLO) Output Over Voltage Protection (OVP) Output Short Protection (OSP) Over Current Protection (OCP) Thermal Fold-Back Protection (TFP) Over Temperature Protection (OTP)
• Low System Cost • Package: SO-8EP • Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
• General LED Lighting Driver with Dimming Function • General Purpose Constant Current Source • Smart LED Lighting
• Halogen and Antimony Free. “Green” Device (Note 3)
Notes:
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"
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.
AL1672
Document number: DS39344 Rev. 2 - 3
1 of 14 www.diodes.com
February 2021
© Diodes Incorporated
Typical Applications Circuit
AL1672
F1
AC Input
VR1
L1
C1 DB1
RTH
D1
C2
CVCC
PWM/DC Signal
RCOMP CCOMP
5
7
VCC APWM
FB
6
8
COMP
DRAIN DRAIN
3 4
GND CS
2
1
RCS
R4
R5 R6
Pin Descriptions
AL1672 BUCK Application Circuit
R3
+C
OUT
4
D2
L2
Pin Number
1 2 3,4 5 6 7 8 9
Pin Name
CS GND DRAIN VCC FB APWM COMP Exposed Pad
Function
Current sense pin, connect this pin to the source of the primary switch Ground Drain of internal MOS Supply voltage of gate driver and control circuits of the IC
The feedback voltage sensing from the auxiliary winding Analog dimming input pin or PWM signal input pin in PWM dimming mode Loop compensation pin Drain of internal MOS
AL1672
Document number: DS39344 Rev. 2 - 3
2 of 14 www.diodes.com
February 2021
© Diodes Incorporated
AL1672
Functional Block Diagram
6
FB
APWM
7
DIM VREF Control
OVP
Valley Detector
OTP
Logical Control
TFP
VCC
5
UVLO &Bias
VREF
S Q
D
3,4,9
Driver
DRAIN
1
CS
-G
+m VREF
+ -
8
COMP
AL1672 Block Diagram
TFP Temperature OTP Detector
2
GND
AL1672
Document number: DS39344 Rev. 2 - 3
3 of 14 www.diodes.com
February 2021
© Diodes Incorporated
AL1672
Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) (Note 4)
Symbol VCC VCS VFB
VCOMP VDRAIN
IDS VAPWM
TJ TSTG TLEAD PD θJA θJC
-
Parameter Power Supply Voltage Voltage at CS to GND FB Input Voltage Loop Compensation Pin Drain Voltage of Internal MOS Continuous Drain Current TC = +25°C Voltage at APWM to GND Operating Junction Temperature Storage Temperature Lead Temperature (Soldering, 10 sec) Power Dissipation at TA=+50°C (Note 5) Thermal Resistance (Junction to Ambient) (Note 5) Thermal Resistance (Junction to Case) (Note 5) ESD (Human Body Model) ESD (Machine Model)
Rating -0.3 to 30 -0.3 to 7 -0.3 to 7 -0.3 to 7
600 4
-0.3 to 7 -40 to +150 -65 to +150
+300 1.53 65 22.4 2000 200
Unit V V V V V A V °C °C °C W
°C/W °C/W
V V
Notes:
4. Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability. All voltages unless otherwise stated and measured with respect to GND.
5. Device mounted on 2"x2" FR-4 substrate PCB, 2oz copper, with minimum recommended pad layout.
Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.)
Note:
S.