AL5812

AL5812
60V, 150mA ADJUSTABLE LINEAR LED DRIVER
Description
Pin Assignments
(Top View)
The AL5812 is an adjustable Linear LED driver offering excellent
temperature stability and output handling capability.
The AL5812
simplifies the design of linear and isolated or non-isolated LED
drivers by setting the LED current with standard value resistors.
The AL5812 has an open drain output that can swing from 1V up to
VCC 1
8 LED
NC 2
7 NC
NC 3
6 NC
RSET 4
60V enabling it drive long LED chains. Its low 0.5V RSET pin is outside
of the LED current path and so accuracy is maintained while
MSOP-8EP
minimizing the required overheads to regulate the LED current. This
reduces its power dissipation when compared to traditional linear
LED drivers.
5 GND
(Top View)
This makes it ideal for driving LEDs up to 150mA
VCC 1
(commonly referred to as ½W LEDs).
6 LED
Longer LED chains can be driven by tapping VCC from the chain,
5 NC
NC 2
where the chain voltage may exceed 60V.
The AL5812 is available in the exposed pad MSOP-8EP and
RSET 3
U-DFN3030-6 packages.
Exposed
Pad
4 GND
U-DFN3030-6
Features
Applications

Low Reference Voltage (VRSET = 0.5V)

Isolated Offline LED Converters

-40°C to +125°C Temperature Range

Linear LED Driver

±3% LED Current Tolerance

LED Signs

Low Temperature Drift

Instrumentation Illumination

1V to 60V Open-Drain Output

High Power Supply Rejection

MSOP-8EP and U-DFN3030-6

Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

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 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.
Typical Applications Circuit
AL5812
Document number: DS35616 Rev. 4 - 2
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AL5812
Pin Descriptions
Pin
Name
Pin
Number
(MSOP8-EP)
Pin
Number
(U-DFN3030-6)
VCC
1
1
RSET
4
3
GND
LED
NC
5
8
2, 3, 6, 7
4
6
2, 5
EP
EP
EP
Function
Power Supply Input.
Connect a 0.1μF ceramic capacitor between VCC and GND as close as possible to the
device.
LED Current Setting Pin.
Connect a resistor from this pin to GND:
ILED = 750/RSET
May also be used to provide PWM dimming functionality.
Ground Reference Point of Device.
LED Current Sink Output.
No Connection.
Exposed Pad (bottom).
Used to improve thermal impedance of package.
It must be connected to GND directly underneath the package but not used as sole GND
potential terminal.
Functional Block Diagram
AL5812
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AL5812
Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.)
Symbol
VCC
VLED
VRSET
ILED
ESD HBM
ESD CDM
TJ
TST
Parameters
Supply Voltage Relative to GND Pin (Note 4)
LED Pin Voltage Relative to GND Pin (Note 4)
RSET Pin Voltage Relative to GND Pin
LED Pin Current Sink Current Range
Human Body Model ESD Protection
Charged Device Model ESD Protection
Operating Junction Temperature
Storage Temperature
Ratings
-0.3 to +66
-0.3 to +66
-0.3 to +6
165
1
1.2
-40 to +150
-55 to +150
Unit
V
V
V
mA
kV
kV
°C
°C
Note:
4.VCC pin can be greater or smaller than VLED; neither should go below GND.
Caution:
Stresses greater than the 'Absolute Maximum Ratings' specified above, may cause permanent damage to the device. These are stress ratings only;
functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device reliability may be
affected by exposure to absolute maximum rating conditions for extended periods of time.
Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when
handling and transporting these devices.
Package Thermal Data
Package
θJC
Thermal Resistance
Junction-to-Case
(Note 7)
MSOP-8EP
U-DFN3030-6
39
14
Notes:
θJA
Thermal Resistance
Junction-to-Ambient
(Note 7)
90°C/W (Note 5)
69°C/W (Note 6)
PDIS
TA = +25°C, TJ = +125°C
(Note 7)
1.1W
1.47W
5. Test condition for MSOP-8EP: Device mounted on FR-4 PCB (51mm x 51mm 2oz copper, minimum recommended pad layout on top layer and
thermal vias to bottom layer ground plane. For better thermal performance, larger copper pad for heat-sink is needed.
6. Test condition for U-DFN3030-6: Device mounted on FR-4 PCB (51mm x 51mm 2oz copper, minimum recommended pad layout on top layer and
thermal vias to bottom layer with maximum area ground plane. For better thermal performance, larger copper pad for heat-sink is needed
7. Dominant conduction path via exposed pad.
Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.)
Symbol
VCC
VLED
ILED
TA
Notes:
Parameter
Supply Voltage Range Relative to GND Pin
LED Pin Output Voltage Range Relative to GND Pin
LED Pin Current (Notes 8 & 9)
Operating Ambient Temperature Range
Min
3.5
1
10
-40
Max
60
60
150
+125
Unit
V
mA
°C
8. For improved accuracy LED current should be greater than 60mA.
9. Maximum LED current is also limited by ambient temperature and power dissipation such that junction temperature should be kept less than or equal
to +125°C.
AL5812
Document number: DS35616 Rev. 4 - 2
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AL5812
Electrical Characteristics (@TA = +25°C, VCC= 3.5V, VLED=1V (Note 10), RSET = 7.5kΩ unless otherwise specified.)
Symbol
VRSET
Parameter
RSET Voltage
Conditions
—
Min
Typ
Max
Unit
—
0.5
—
V
57
60
63
142.5
150
157.5
97
100
103
TA = -40°C to +125°C
95
—
105
TA = -40°C to +125°C
RSET = 12.5kΩ
ILED
ILED Current Accuracy
TA = +25°C
RSET = 4.99kΩ
RSET = 7.5kΩ
REGLINE
UVLO
ICC
ILEAK
mA
LED Current Line Regulation
VCC = 3.5V to 60V
TA = +25°C
—
0.25
—
%
Under Voltage Lockout
—
TA = -40°C to +125°C
—
2
—
V
TA = +25°C
—
320
400
TA = -40°C to +125°C
—
—
500
TA = +125°C
—
—
1
Supply Current
3.5V ≤ VCC ≤ 60V
LED Pin Leakage Current
VCC = VLED = 60V
RSET = Open Circuit
µA
µA
TSHDN
Thermal Shutdown
—
—
—
155
—
C
THYS
Thermal Shutdown Hysteresis
—
—
—
20
—
C
Note:
10. All voltages unless otherwise stated are measured with respect to GND pin.
AL5812
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AL5812
Typical Performance Characteristics
145
160
120
LED CURRENT (mA)
120
LED CURRENT (mA)
RSET = 4.99k
140
RSET = 4.99k
140
100
RSET = 7.5k
80
60
RSET = 12.4k
100
RSET = 7.5k
80
60
RSET = 12.4k
40
40
0
0
5
VLED = 1.2V
VCC = 3.5V
20
VLED = 1.2V
TA = +25°C
20
0
-40 -25 -10
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Figure 2 LED Current vs. Ambient Temperature
10 15 20 25 30 35 40 45 50 55 60
INPUT VOLTAGE (V)
Figure 1 LED Current vs. Input Voltage
160
VIN = 3.5V
TA = +25°C
RSET = 4.99k
5
RSET = 4.99k
140
VIN = 3.5V
TA = +25°C
LED CURRENT (mA)
LED CURRENT (mA)
120
RSET = 7.5k
RSET = 12.4k
100
RSET = 7.5k
80
60
RSET = 12.4k
40
20
0
0
0
5
10
15
20
25
30
LED VOLTAGE (V)
Figure 3 LED Current vs. LED Pin Voltage (Note 11)
160
R SET = 4.99k
140
140
120
120
R SET = 7.5k
100
80
60
RSET = 12.4k
40
0
RSET = 4.99k
100
RSET = 7.5k
80
60
RSET = 12.4k
40
TA = +25°C
2 LEDs
20
Notes:
1.0
1.5
2.0
2.5
3.0
LED VOLTAGE (V)
Figure 4 LED Current vs. LED Pin Voltage Zoomed
LED CURRENT (mA)
LED CURRENT (mA)
160
0.5
TA = +25°C
VCC pin tied to LED pin
2 LEDs
20
0
5
10
15
20 25 30 35 40 45
INPUT VOLTAGE (V)
Figure 5 LED Current vs. Input Voltage - 2 LEDs
(Note 11 & 12)
0
0
2
4
6
8 10 12 14 16 18 20 22
INPUT VOLTAGE (V)
Figure 6 LED Current vs. Input Voltage
2 LEDs - High Side Drive (Notes 11, 12 &13)
11. These curves have been limited at larger input voltages due to power dissipation.
12. Lower input voltage range is limited by the LED chain voltage
13. The AL5812 has its VCC pin connected to its LED pin, which are connected to the positive input supply voltage. RSET is connected to AL5812 GND
pin, which is connected to the anode of the LED chain. This creates a high side driver of the LED chain. See Figure 15.
AL5812
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AL5812
Typical Performance Characteristics (cont.)
14
110
TA = +25°C
2 LEDs
RSET = 7.5k
fPWM = 100Hz
100
80
70
60
50
40
THYS
10
8
6
4
30
2
20
0
10
0
TSHDN
R SET = 75K
12
LED CURRENT (mA)
LED CURRENT (mA)
90
V IN = 9V
0
10
20
-2
125
30
40 50 60 70 80 90 100
DUTY CYCLE (%)
Figure 7 LED Current vs. PWM Duty Cycle
0.500
130
135
140
145
150
155
TEMPERATURE (°C)
Figure 8 LED Current vs. TSHDN
0.500
VLED = 1.2V
TA = +25°C
VLED = 1.2V
VIN = 3.5V
0.495
0.495
RSET VOLTAGE (V)
RSET VOLTAGE (V)
160
0.490
0.485
0.490
RSET = 7.5k
0.485
RSET = 7.5k
0.480
0.480
0.475
0
5
0.475
-40 -25 -10
10 15 20 25 30 35 40 45 50 55 60
INPUT VOLTAGE (V)
Figure 9 RSET Voltage vs. Input Voltage
20 35 50 65 80 95 110 125
TEMPERATURE (C)
Figure 10 RSET Voltage vs. Ambient Temperature
350
400
300
RSET = 4.99k
300
250
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
350
RSET = 7.5k
200
RSET = 12.4k
150
100
0
RSET = 7.5k
200
RSET = 12.4k
150
100
10 15 20 25 30 35 40 45 50 55 60
INPUT VOLTAGE (V)
Figure 11 Supply Current vs. Input Voltage
Document number: DS35616 Rev. 4 - 2
VLED = 1.2V
VIN = 3.5V
50
5
AL5812
R SET = 4.99k
250
VLED = 1.2V
T A = +25°C
50
0
5
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0
-40 -25 -10
5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Figure 12 Supply Current vs. Ambient Temperature
March 2014
© Diodes Incorporated
AL5812
Application Information
Description
The AL5812 is a Linear LED driver and in normal operation has the LEDs connected to the same potential as its VCC pin and regulates the LED
current by sinking current into to its LED pin see Figure 13.
The LED current is set by the use of an external resistor, RSET, connected from the RSET pin to GND. This resistor supplies the bias current of the
AL5812 together with current regulator to set the LED current.
The nominal LED current is determined by this equation:
ILED  1500 *
0.5
R SET
where 1500 is the current ratio between the LED pin current and RSET pin current.
With RSET = 7.5k
ILED  1500 *
0 .5
 100mA
7.5k
The AL5812 with its 60V capability on its supply pin, VCC, and its LED drive pin allows it to operate from supply rails up to 60V and/or directly
drive LED chains up to 60V as shown in Figures 13 and 14. The voltage applied to the VCC pin can be greater or lower than the voltage applied
to the LED string. Figure 14 shows where you might control it from a 5-V rail but power the rails from a 12V rail.
VLED
VIN
VCC
CIN 0.1µF
LED
AL5812
RSET
GND
RSET = 4.99kΩ
Figure 14 Low Side Drive – Separate Supplies
Figure 13 Low Side Current LED Setting
AL5812
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AL5812
Application Information (cont.)
High Voltage Operation
An extension of Figure 14 is to derive the power for the AL5812 from the LED chain itself see Figure 15. LED chains greater than 60V can be
driven in this manner as long PWM dimming is not utilized.
Figure 16 High Side Current LED String
Figure 15 Low Side LED String Tapping
Figure 15 shows the use of RC delay to match the power time delay between Vcc and LED pin. The AL5812 can also be used on the high side of
the LEDs, see Figure 16. This is a simple way of extending the maximum LED chain voltage, however, it does increase the minimum system input
voltage to:
Where
VIN(min) = VLED_CHAIN + 3.5V.
VLED_CHAIN is the LED chain voltage.
AL5812
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AL5812
Application Information (cont.)
PWM Dimming
The AL5812 can be used to provide LED current dimming driving the RSET pin via the current setting resistor (RSET) and a series MOSFET switch
to ground (Figure 17). The RSET pin current is then effectively switched on and off causing the LED current to turn on and off. The linearity is
shown in Figure 18.
110
TA = +25°C
2 LEDs
RSET = 7.5k
fPWM = 500Hz
100
LED CURRENT (mA)
90
80
70
60
50
40
30
20
10
0
Figure 17 PWM Dimming
0
10
20
30
40 50 60 70 80 90 100
DUTY CYCLE (%)
Figure 18 PWM Dimming Linearity
Thermal Considerations
When designing linear LED drivers careful consideration must be given to:
1.
the power dissipation within the LED driver
and
2.
PCB layout/heat sinking.
A Linear LED driver has to be able to handle the large potential input voltage variations due to the supply voltage tolerance and also the variation
in LED forward voltage due to binning and temperature.
This can result in a large potential difference across the LED driver resulting in a larger than anticipated power dissipation.
For example in an 12V powered system with a 5% output voltage tolerance; the input voltage could typically vary from 12.6V down to 11.4V
driving 3 LEDs with a voltage varying from 3V to 3.5V at 100mA. This means that the LED driver has to cope with a voltage drop across varying
from approximately 3.6V to 0.9V. This means that the power dissipation of the AL5812 could be as much as 366mW.
Figure 19 below shows how the AL5812’s power dissipation capability varies with package; these values will vary with PCB size and area of
metal associated with the ground plane used for heat sinking. By increasing the area on the top layer the thermal impedance of both packages
could be improved.
1.6
POWER DISSIPATION (W)
1.4
U-DFN3030-6
1.2
1.0
MSOP-8EP
0.8
0.6
0.4
0.2
0.0
-40 -25 -10 5 20 35 50 65 80 95 110 125
AMBIENT TEMPERATURE (C)
Figure 19 Power Dissipation Derating
AL5812
Document number: DS35616 Rev. 4 - 2
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AL5812
Ordering Information
AL5812 XX - XX
Package
Packing
FF : U-DFN3030-6
7 : 7” Tape & Reel
MP : MSOP-8EP
13 : 13” Tape & Reel
Device
Package Code
Packaging
AL5812MP-13
AL5812FF-7
MP
FF
MSOP-8EP
U-DFN3030-6
7”/13” Tape and Reel
Quantity
Part Number Suffix
2500/Tape & Reel
-13
3000/Tape & Reel
-7
Marking Information
(1) MSOP-8EP
(Top View)
8
7
Logo
6
5
YW X E
Part Number
AL5812
1
2
3
A~Z : Green
MSOP-8EP
Y : Year : 0~9
W : Week: A~Z : 1~26 week;
a~z : 27~52 week;
z represents 52 and 53 week
4
(2) U-DFN3030-6
( Top View )
XX
YW X
Part Number
AL5812FF-7
AL5812
Document number: DS35616 Rev. 4 - 2
XX : Identification Code
Y : Year : 0~9
W : Week : A~Z : 1~26 week;
a~z : 27~52 week; z represents
52 and 53 week
X : A~Z : Green
Package
U-DFN3030-6
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Identification Code
B9
March 2014
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AL5812
Package Outline Dimensions (All dimensions in mm.)
Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for latest version.
(1) MSOP-8EP
D
4X
10
°
x
E
0.25
D1
E2
Gauge Plane
Seating Plane
a
y
1
4X
10
°
8Xb
e
Detail C
E3
A1
A3
c
A2
A
D
L
E1
See Detail C
MSOP-8EP
Dim Min Max Typ
A
1.10
A1
0.05 0.15 0.10
A2
0.75 0.95 0.86
A3
0.29 0.49 0.39
b
0.22 0.38 0.30
c
0.08 0.23 0.15
D
2.90 3.10 3.00
D1
1.60 2.00 1.80
E
4.70 5.10 4.90
E1
2.90 3.10 3.00
E2
1.30 1.70 1.50
E3
2.85 3.05 2.95
e
0.65
L
0.40 0.80 0.60
a
0°
8°
4°
x
0.750
y
0.750
All Dimensions in mm
(2) U-DFN3030-6
3
A
1
A
A
e
n
a
l
P
g
n
i
t
a
e
S
2
D D
U-DFN3030-6
Dim Min
Max
Typ
A
0.57 0.63 0.60
A1
0
0.05 0.02
A3
0.15
b
0.35 0.45 0.40
D
2.95 3.05 3.00
D2
2.25 2.45 2.35
E
2.95 3.05 3.00
E2
1.48 1.68 1.58
e
0.95
L
0.35 0.45 0.40
Z
0.35
All Dimensions in mm
D
I
1
#
n
i
P
︵
︶
5
3
.
0
*
5
3
.
0
°
5
4
︵
︶
L
2
E
E
e
AL5812
Document number: DS35616 Rev. 4 - 2
b
x
4
Z
︵ ︶
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AL5812
Suggested Pad Layout
Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for latest version.
(1) MSOP-8EP
X
C
Dimensions
Y
G
Y2
C
G
X
X1
Y
Y1
Y2
Y1
X1
Value
(in mm)
0.650
0.450
0.450
2.000
1.350
1.700
5.300
(2) U-DFN3030-6
2 1
X X
C
Dimensions
2
Y
1
Y
9
0
4
.
0
C
Document number: DS35616 Rev. 4 - 2
Y
X
AL5812
C
X
X1
X2
Y
Y1
Y2
Value
(in mm)
0.950
0.500
2.400
2.550
0.600
1.780
3.300
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AL5812
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AL5812
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