AL8823 - Diodes Incorporated
AL8823
MR16 SINGLE BOOST LED CONTROLLER
NEW PRODUCT
Description
Pin Assignments
The AL8823 is a boost controller that delivers an accurate constant
current for MR16, AR111 and similar LED Lamps. With proprietary
control scheme, the LED driver is compatible with many commonly
used electronic transformers and provides designs with High Power
Factor (PF) and low Total Harmonic Distortion (THD) for these
applications. The operation frequency is up to 1MHz that allows the
use of small size inductor. With external MOS, the AL8823 can be
used for wide range of output powers. The driver can be used for
dimmable MR16, AR111 application and can be compatible with
leading-edge dimmer and trailing-edge dimmer. The AL8823 is
available in package SO-8.
(Top View)
CS
1
8
NC
FB
2
7
OUT
COMP
3
6
VCC
GND
4
5
VIN
Features

Wide Input Voltage Range: 5V to 36V

Continuous Conduction Mode (CCM) Operation

Up to 1MHz Switching Frequency

Applications
High PF > 0.9 and Low THD < 30% and Low Ripple < 20%

Compatible with Leading-edge Dimmer and Trailing-edge
Dimmer



SO-8

Internal Protections


Under Voltage Lock Out (UVLO)

Output Open Protection

Over Temperature Protection (OTP)
Pb-free SO-8 pacakge

Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

Halogen and Antimony Free. “Green” Device (Note 3)
Notes:
Non-dimmable MR16, AR111 Lamps
Dimmable MR16, AR111 Lamps
General Illumination Lamps
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.
AL8823
Document number: DS39232 Rev. 1 - 2
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AL8823
Typical Applications Circuit
L
D1
Vac
D2
D5
D3
D4
CO
NEW PRODUCT
Q1
RSET
RHYS
OUT
VCC
C3
AL8823
CS
VIN
FB
COMP
GND
RFB
C4
The AL8823 Boost Application Circuit
Pin Descriptions
Pin Number
Pin Name
1
CS
Input Current Sense Pin
2
FB
LED Output Current Feedback Pin
3
COMP
4
GND
Ground
5
VIN
IC Input Voltage, Adding from Boost Output Voltage
6
VCC
Supply Voltage For Internal Circuit
7
OUT
Gate Driver Output
8
NC
AL8823
Document number: DS39232 Rev. 1 - 2
Function
Control Loop Compensation Pin
Not Connected
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AL8823
Functional Block Diagram
VIN
VCC
5
6
VCC
NEW PRODUCT
Internal
Regulator
VREF
4
VBG
UVLO
GND
Chip_EN
VBG
Bandgap
VIN
OVP
PWM1
OVP
LOGIC
1
IHYS
OTP
VFB
CS
CS1
OTP
VCS1
VCC
Driver
7
OUT
COMPARATOR
2
FB
PWM1
EA
IHYS
VBG
3
COMP
The AL8823 Block Diagram
AL8823
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AL8823
Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified. Note 4)
Symbol
Parameter
NEW PRODUCT
Unit
VIN
VIN Pin Voltage
-0.3 to 40
V
VOUT
OUT Pin Voltage
-0.3 to 6
V
COMP Pin Voltage
-0.3 to 6
V
VCS
CS Pin Voltage
-0.3 to 6
V
VFB
FB Pin Voltage
-0.3 to 6
V
VCC
VCC Pin Voltage
-0.3 to 6
V
+150
°C
-65 to +150
°C
VCOMP
TJ
Operating Junction Temperature
TSTG
Storage Temperature
θJA
Thermal Resistance (Junction to Ambient) (Note 5)
104
°C/W
JC
Thermal Resistance (Junction to Case) (Note 5)
6.6
°C/W
Lead Temperature (Soldering, 10sec)
+300
°C
–
ESD (Machine Model)
200
V
–
ESD (Human Body Model)
2000
V
TLEAD
Notes:
Rating
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.
5. Device mounted on 1"x1" FR-4 substrate PCB, 2oz copper, with minimum recommended pad layout.
Recommended Operating Conditions
Symbol
Note 6:
Parameter
VIN
VIN Pin Voltage
TA
Ambient Temperature (Note 6)
Min
Max
Unit
5
36
V
-40
+105
°C
The device may operate normally at +125°C ambient temperature under the condition not trigger temperature protection.
AL8823
Document number: DS39232 Rev. 1 - 2
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AL8823
Electrical Characteristics (@TA = +25°C, unless otherwise specified.)
Symbol
Parameter
Condition
Min
Typ
Max
Unit
NEW PRODUCT
Input Supply
VIN
VIN Pin Voltage
–
5
–
36
V
IQ
Quiescent Current
No Switching
–
1
–
mA
VUVLO
Under-Voltage Lockout
Voltage
VIN Rising
–
4.2
–
V
VHYS
UVLO Hysteresis
–
–
500
–
mV
VCC Pin Voltage
–
4.5
5
5.5
V
–
Source Current Capability
VCC = 5V
10
–
–
mA
–
Load Regulation
–
–
4
–
%
VOH
Output High Level Voltage
–
4.5
5
–
V
VOL
Output Low Level Voltage
–
–
–
0.4
V
tR
Output Voltage Rise Time
C=1nF
–
32
–
ns
tF
Output Voltage Fall Time
C=1nF
–
26
–
ns
VCC Regulator
VCC
Gate Driver Output
Compensation and Soft Start (COMP Pin)
GEA
Error Amplifier Transconductance
–
–
1000
–
µA/V
IO-H
Sourcing Current
VCOMP = 0.5V
–
68
–
µA
IO-L
Sinking Current
VCOMP = 4.5V
–
68
–
µA
VFB
FB Pin Voltage
–
215
222
229
mV
Boost Sense Voltage Low
Level
VCOMP = 0V
–
-90
–
mV
Hysteresis Current
–
85
100
115
µA
TOTSD
Thermal Shutdown (Note 7)
–
–
+160
–
°C
THYS
Thermal Shutdown Hysteresis
(Note 7)
–
–
+40
–
°C
Hysteresis Comparator
VCS_MIN
IHYS
Over-Temperature Protection
Note 7:
These parameters, although guaranteed by design, are not 100% tested in production.
AL8823
Document number: DS39232 Rev. 1 - 2
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AL8823
Performance Characteristics
Quiescent Current vs. VIN Pin Voltage
Quiescent Current vs. Ambient Temperature
1.0
1.2
1.1
Quiescent Current (mA)
Quiescent Current (mA)
1.0
0.9
0.8
0.7
0.6
0.8
0.7
0.6
0.5
0.5
4
8
12
16
20
24
28
32
-45
36
-30
-15
0
30
45
60
75
90
105
Ambient Temperature ( C)
Under-Voltage Lockout Voltage vs. VIN Pin Voltage
Under-Voltage Lockout Voltage vs. Ambient Temperature
4.5
4.5
4.4
4.4
Under-Voltage Lockout Voltage
Sense Voltage Low Level (mV)
15
o
VIN Pin Voltage (V)
4.3
4.2
4.1
4.0
4.3
4.2
4.1
4.0
3.9
3.9
4
8
12
16
20
24
28
32
-45
36
-30
-15
0
15
30
45
60
75
90
105
o
VIN Pin Voltage (V)
Ambient Temperature ( C)
FB Pin Voltage vs.VIN Pin Voltage
FB Pin Voltage vs. Ambient Temperature
240
240
235
235
230
230
FB Pin Voltage (mV)
FB Pin Voltage (mV)
NEW PRODUCT
0.9
225
220
215
210
225
220
215
210
205
205
200
200
4
8
12
16
20
24
28
32
36
Document number: DS39232 Rev. 1 - 2
-30
-15
0
15
30
45
60
75
90
105
o
VIN Pin Voltage (V)
AL8823
-45
Ambient Temperature ( C)
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AL8823
Performance Characteristics (Cont.)
Boost Sense Voltage Low Level vs.
VIN Pin Voltage
Boost Sense Voltage Low Level vs.
Ambient Temperature
Sense Voltage Low Level (mV)
Sense Voltage Low Level (mV)
-90
-85
-80
-75
-70
4
8
12
16
20
24
28
32
-85
-80
-75
-70
36
-45
-30
-15
VIN Pin Voltage (V)
0
15
30
45
60
75
90
105
o
Ambient Temperature ( C)
Hysteresis Current vs. VIN Pin Voltage
Hysteresis Current vs. Ambient Temperature
120
120
115
115
Hysteresis Current (uA)
Hysteresis Current (uA)
NEW PRODUCT
-90
110
105
100
95
110
105
100
95
90
90
4
8
12
16
20
24
28
32
36
-45
Document number: DS39232 Rev. 1 - 2
-15
0
15
30
45
60
75
90
105
o
VIN Pin Voltage (V)
AL8823
-30
Ambient Temperature ( C)
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AL8823
Application Information
Operation
The AL8823 is a boost converter that delivers an accurate constant current for driving LEDS. With hysteretic control scheme, the LED driver is
compatible with most of commonly used electronic transformers. The driver can be compatible with leading-edge dimmer and trailing-edge dimmer.
L
D1
Vac
D2
D5
D3
D4
CO
NEW PRODUCT
Q1
RSET
RHYS
OUT
VCC
C3
VIN
AL8823
CS
FB
RFB
COMP
GND
C4
Figure 1. Typical Application Circuit
LED Current Control
The LED current is controlled by the resistor RFB in Figure 1.
Connected between FB pin and Ground, the nominal average output current in the LED(s) is defined as:
ILED 
0.222
RFB
RSET and RHYS Setting
The Boost converter of the AL8823 operates at continuous conduction mode and is based on hysteresis schematic which has lower threshold and
upper threshold. Refer to Figure 2 depicting the inductor current waveform.
IL
Peak or Upper Threshold
ΔIL
IL(peak)
IL(ave)
IL(val)
Valley or Lower Threshold
tON
tOFF
Time
Figure 2. Inductor Current
When switch SW is turned on, the inductor current flows through R SET and ramps up linearly. The rising current produces a voltage ramp across
RSET. When the voltage across RSET reaches the upper threshold, switch SW is turned off. The inductor current continues to flow through R SET but
decays. The decaying current produces a falling voltage at RSET. When the voltage across RSET falls to the lower threshold, switch SW is turned
on again.
The lower threshold voltage VLT depends on the voltage VCOMP at COMP pin that varies with the input voltage and output load. The equation is
shown as below.
AL8823
Document number: DS39232 Rev. 1 - 2
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AL8823
Application Information (Cont.)
 (VCOMP  1.5)  0.6  1.4
V ,1.5V  VCOMP  5V

VLT  
16
0.088V , 0V  VCOMP  1.5V
The range of VCOMP is from 0V to 5V.
NEW PRODUCT
The upper threshold depends on the lower threshold and the hysteresis value. The hysteresis value is set by external resister RHYS. It is defined as
below.
VHYS  RHYS 100 A
According to the operation principle , the peak to peak current ∆IL and the valley current IL(val) can be obtained by the below equations.
I L ( val ) 
I L 
VLT
RSET
VHYS
RSET
Where:
∆IL is the peak to peak current of inductor.
IL(val) is the valley current of inductor.
From the Figure 2, the relationship between IL(peak), IL(val), IL(ave) and ∆IL can be obtained as below.
I L ( peak)  I L ( val)  I L
1
I L ( ave)  I L ( val )   I L
2
Where:
IL(peak) is the peak current of inductor.
IL(ave) is the average current of inductor.
As we know the average current IL(ave) depends on the output power, rated input voltage VIN1 of step-up converter and total efficiency η. So the
average current IL(ave) can be obtained by the following equation.
I L ( ave) 
(VLED  0.222)  I LED
  VIN 1
Where: VLED is the voltage in LEDs.
Set ratio of ∆IL to IL(peak) as K.
AL8823
Document number: DS39232 Rev. 1 - 2
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AL8823
Application Information (Cont.)
I L
K
I L ( peak)
NEW PRODUCT
RSET and RHYS can be obtained from above equations:
 ((VCOMP  1.5)  0.6  1.4)  (2  K )   VIN 1
1.5V  VCOMP  5V

32  (VLED  0.222)  I LED (1-K)

RSET = 
 0.044  (2  K )   VIN 1 , 0V  V
COMP  1.5V
 (VLED  0.222)  I LED (1-K)
RHYS =
2  (VLED  0.222)  I LED  K  RSET 104
  VIN 1  (2  K )
When the value of K, η and VCOMP are provided, the value of resister RSET and RHYS can be calculated according to these above equations. In
order to get appropriate efficiency and Electronic Transformer (ET) compatibility, generally K is set between 0.4 and 0.8. Due to the range of
VCOMP is from 0V to 5V, in order to get output voltage regulation, generally VCOMP is set as 3V at rated input voltage.
Inductor Selection
Because of the using of the hysteretic control scheme, the switching frequency in a boost configuration can be adjusted in accordance to the value
of the inductor being used. The value of the inductor can be determined on the desired switching frequency by using the following equation:
L
[VIN 1  ( RSET  RL  RDSON )  I L ( ave ) ]  [VLED  0.222  VF  ( RL  RSET )  I L ( ave )  VIN 1 ]
I L VLED  0.222  VF  RDSON  I L ( ave )   f SW
Where:
L is the coil inductance.
RL is the coil resistance.
RDSON is the switch SW resistance.
VIN1 is the rated input voltage.
VF is the diode forward voltage.
fSW is the desired switching frequency. Generally 500kHz to 800kHz switching frequency is suggested. Low switching frequency can decrease the
switching loss but need to choose higher inductor values that will result in larger size in order to meet the saturation current. For example the
relationship between switching frequency and inductor value is shown as below Table 1 in the same application system. Considering these factors,
500kHz switching frequency is recommend in typical application.
Inductance Value of L @ VAC = 12VAC, VIN = 22V
VLED = 28V, ILED = 180mA
Operation Frequency of SW at Peak Voltage Of VAC
10µH
840kHz
15µH
800kHz
22µH
680kHz
33µH
465kHZ
Table 1
AL8823
Document number: DS39232 Rev. 1 - 2
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AL8823
Application Information (Cont.)
VIN OVP Protection
AL8823 has an internal over voltage protection to protect IC from excessive input voltage. When the voltage applied at VIN pin exceeds 39V, it
will turn off the power switch. The power switch will be turned on again once the voltage at V IN drops below 34V.
NEW PRODUCT
VCC Regulator
The VCC pin requires a capacitor C3 for stable operation and to store the charge for the large GATE switching currents. Choose a 10V rated low
ESR, X7R or X5R, ceramic capacitor for best performance. A 4.7µF capacitor will be adequate for many applications. Place the capacitor close to
the IC to minimize the trace length to the VCC pin and to the IC ground.
An internal current limit on the VCC output protects the excessive on-chip power dissipation. The VCC pin has set the output to 5V (typ.) to protect
the internal FETs from excessive power dissipation caused by not being fully enhanced. If the VCC pin is used to drive extra circuits beside the
AL8823, the extra loads should be limited to less than 8mA.
Output Capacitor CO
The capacitor CO is used to hold the bus voltage and reduce the ripple of LED current when the electronic transformer has no output. For most
applications, it is recommended to use an aluminum electrolytic capacitor with greater than 220µF capacitance.
Compensation Capacitor C4
In applications powered by electronic transformer, the input voltage can change roughly in one cycle of AC power frequency. A 1µF ceramic
capacitor C4 connected from COMP pin to ground help to stabilize the control loop of the regulator.
Diode Selection
For maximum efficiency and performance, the rectifiers (D5) should be fast low capacitance Schottky diodes with low reverse leakage at
maximum operating voltage and temperature. With its low power dissipation, the Schottky diode outperforms other silicon diodes and increases
overall efficiency.
Over Temperature Protection
An over temperature protection feature is to protect the AL8823 from excessive heat damage. When the junction temperature exceeds +160°C,
the internal FET will be turned off. When junction temperature drops below +120°C, IC will turn on both FETs and return to normal operation.
AL8823
Document number: DS39232 Rev. 1 - 2
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AL8823
Ordering Information
NEW PRODUCT
AL8823 X - X
Package
Packing
S : SO-8
13 :13" Tape & Reel
Part Number
Package Code
Package
AL8823S-13
S
SO-8
13” Tape and Reel
Quantity
Part Number Suffix
2500/Tape & Reel
-13
Marking Information
(Top View)
8
7
6
5
Logo
Part Number
YY : Year : 15, 16, 17~
WW : Week : 01~52; 52
Represents 52 and 53 Week
X X : Internal Code
AL8823
YY WW X X
1
AL8823
Document number: DS39232 Rev. 1 - 2
2
3
4
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AL8823
Package Outline Dimensions (All dimensions in mm(inch).)
Please see http://www.diodes.com/package-outlines.html for the latest version.
Package Type: SO-8
NEW PRODUCT
(1)
E
1
b
E1
h
)
ides
All s
9° (
R
0
e
c
4° ± 3°
A
.1
Q
45°
7°
A1
L
E0
Gauge Plane
Seating Plane
SO-8
Dim
Min
Max
Typ
A
1.40
1.50
1.45
A1
0.10
0.20
0.15
b
0.30
0.50
0.40
c
0.15
0.25
0.20
D
4.85
4.95
4.90
E
5.90
6.10
6.00
E1
3.80
3.90
3.85
E0
3.85
3.95
3.90
e
--1.27
h
-0.35
L
0.62
0.82
0.72
Q
0.60
0.70
0.65
All Dimensions in mm
D
Suggested Pad Layout
Please see http://www.diodes.com/package-outlines.html for the latest version.
(1)
Package Type: SO-8
X1
Dimensions Value (in mm)
C
1.27
X
0.802
X1
4.612
Y
1.505
Y1
6.50
Y1
Y
C
AL8823
Document number: DS39232 Rev. 1 - 2
X
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AL8823
IMPORTANT NOTICE
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
NEW PRODUCT
Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes
without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or
trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume
all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated
website, harmless against all damages.
Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel.
Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and
hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or
indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.
Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings
noted herein may also be covered by one or more United States, international or foreign trademarks.
This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the
final and determinative format released by Diodes Incorporated.
LIFE SUPPORT
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express
written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the
labeling can be reasonably expected to result in significant injury to the user.
B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and
acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any
use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related
information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its
representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2017, Diodes Incorporated
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AL8823
Document number: DS39232 Rev. 1 - 2
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