AL5801
100V, ADJUSTABLE CURRENT SINK LINEAR LED DRIVER
Description
The AL5801 combines a 100V N-channel MOSFET with a pre-
biased NPN transistor to make a simple, small footprint LED driver.
The LED current is set by an external resistor connected from R
EXT
pin (4) to GND pin (6). The internal pre-biased transistor develops
approximately 0.56V across the external resistor.
The AL5801 open-drain output can operate from 1.1V to 100V
enabling it to operate 5V to 100V power supplies without additional
components.
PWM dimming of the LED current can be achieved by driving the
BIAS pin (1) with an external, open-collector NPN transistor or
open-drain N-channel MOSFET.
The AL5801 is available in a SOT26 package and is ideal for driving
LED currents up to 350mA.
Pin Assignments
(Top View)
SOT26
Features
•
•
•
•
•
•
•
•
Feedback Pin Reference Voltage V
RSET
= 0.56V at +25°C
-40°C to +125°C Temperature Range
1.1V to 100V Open-Drain Output
Negative temperature V
RSET
co-efficient automatically reduces
the LED current at high temperatures
Low thermal impedance SOT26 package with copper lead
frame
Lead-Free Finish; RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Qualified to AEC-Q101 Standards for High Reliability
1. EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. All applicable RoHS exemptions applied.
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.
Applications
•
•
•
Linear LED Drivers
LED Signs
Offline LED Luminaries
Notes:
Typical Applications Circuit
AL5801
Document number: DS35555 Rev. 3 - 2
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July 2012
© Diodes Incorporated
AL5801
Pin Descriptions
Pin
Number
1
2
3
4
5
6
Pin
Name
BIAS
FB
OUT
R
EXT
COMP
GND
Biases the open-Drain output MOSFET
Feedback pin
Open-Drain LED driver output
Current sense pin. LED current sensing resistor should be connected from here to GND
Compensation pin. Connect COMP pin to REXT pin and insert a 1nF ceramic capacitor from COMP
pin to FB pin for improved transient stability
Ground reference point for setting the LED current
Function
Functional Block Diagram
Figure 1 Block Diagram
Absolute Maximum Ratings
(@T
A
= +25°C, unless otherwise specified.)
Symbol
V
OUT
V
BIAS
V
FB
V
COMP
V
REXT
I
OUT
T
J
T
ST
Note:
Characteristics
Output voltage relative to GND
BIAS voltage relative to GND (Note 4)
FB voltage relative to GND
COMP voltage relative to GND
REXT voltage relative to GND
Output current
Operating junction temperature
Storage temperature
Values
100
20
6
6
6
350
-40 to +150
-55 to +150
Unit
V
V
V
V
V
mA
°C
°C
4. With pins 5 and 6 connected together.
These are stress ratings only. Operation outside the absolute maximum ratings may cause device failure.
Operation at the absolute maximum rating for extended periods may reduce device reliability.
AL5801
Document number: DS35555 Rev. 3 - 2
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AL5801
Package Thermal Data
Characteristic
Power Dissipation (Note 5) @ T
A
= +25°C
Power Dissipation (Note 6) @ T
A
= +25°C
Power Dissipation (Note 7) @ T
A
= +25°C
Power Dissipation (Note 8) @ T
A
= +25°C
Thermal Resistance, Junction to Ambient Air (Note 5) @ T
A
= +25°C
Thermal Resistance, Junction to Ambient Air (Note 6) @ T
A
= +25°C
Thermal Resistance, Junction to Ambient Air (Note 7) @ T
A
= +25°C
Thermal Resistance, Junction to Ambient Air (Note 8) @ T
A
= +25°C
Notes:
5. Device mounted on 15mm x 15mm 2oz copper board.
6. Device mounted on 25mm x 25mm 1oz copper board.
7. Device mounted on 25mm x 25mm 2oz copper board.
8. Device mounted on 50mm x 50mm 2oz copper board.
Symbol
Value
0.75
0.70
0.85
1.05
165
180
145
120
Unit
P
D
W
R
θ
JA
°C/W
Recommended Operating Conditions
(@T
A
= +25°C, unless otherwise specified.)
Symbol
V
BIAS
V
OUT
I
LED
T
A
Note:
Parameter
Supply voltage range
OUT voltage range
LED pin current (Note 9)
Operating ambient temperature range
Min
3.5
1.1
25
-40
Max
20
100
350
125
Unit
V
mA
°C
9. Subject to ambient temperature, power dissipation and PCB.
NMOSFET Electrical Characteristics: (Q1)
(@T
A
= +25°C, unless otherwise specified.)
Characteristic
OFF CHARACTERISTICS
Drain-Source Breakdown Voltage
Zero Gate Voltage Drain Current
Gate-Source Leakage
ON CHARACTERISTICS
Gate Threshold Voltage
Static Drain-Source On-Resistance
Forward Transconductance
Diode Forward Voltage
DYNAMIC CHARACTERISTICS
Input Capacitance
Output Capacitance
Reverse Transfer Capacitance
C
iss
C
oss
C
rss
⎯
⎯
⎯
129
14
8
⎯
⎯
⎯
pF
pF
pF
V
DS
= 50V, V
GS
= 0V
f = 1.0MHz
V
GS(th)
R
DS (ON)
g
fs
V
SD
2.0
⎯
⎯
⎯
⎯
⎯
⎯
0.9
0.89
4.1
0.85
0.99
⎯
1.1
V
Ω
S
V
V
DS
= V
GS
, I
D
= 250µA
V
GS
= 10V, I
D
= 1.5A
V
GS
= 6V, I
D
= 1A
V
DS
= 15V, I
D
= 1A
V
GS
= 0V, I
S
= 1.5A
Symbol
BV
DSS
I
DSS
I
GSS
Min
100
⎯
⎯
Typ
⎯
⎯
⎯
Max
⎯
1
±100
Unit
V
µA
nA
Test Condition
V
GS
= 0V, I
D
= 250µA
V
DS
= 60V, V
GS
= 0V
V
GS
=
±20V,
V
DS
= 0V
AL5801
Document number: DS35555 Rev. 3 - 2
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July 2012
© Diodes Incorporated
AL5801
Pre-Bias Transistor Electrical Characteristics: (Q2)
(@T
A
= +25°C, unless otherwise specified.)
Characteristic (Note 10)
Input Voltage
Output Voltage
Output Current
DC Current Gain
Input Resistance
Resistance Ratio
Notes:
Symbol
V
I(off)
V
I(on)
V
O(on)
I
O(off)
G
1
R
1
R
2
/R
1
Min
0.4
-
-
-
80
3.2
8
Typ
-
-
0.05
-
-
4.7
10
Max
-
1.5
0.3
0.5
-
6.2
12
Unit
V
V
V
μA
-
kΩ
-
Test Condition
V
CC
= 5V, I
O
= 100μA
V
CC
= 0.3V, I
O
= 5mA
I
O
/I
I
= 5mA/0.25mA
V
CC
= 50V, V
I
= 0V
V
O
= 5V, I
O
= 10mA
-
-
10. Short duration pulse test used to minimize self-heating effect.
Thermal Characteristics
1.2
1.0
50mm x 50mm
(2oz. FR4)
1.2
1.0
T
A
= 25°C
2oz. FR4
MAX POWER DISSIPATION (W)
MAX POWER DISSIPATION (W)
150
0.8
25mm x 25mm
(2oz. FR4)
15mm x 15mm
(2oz. FR4)
0.8
0.6
0.6
0.4
0.4
0.2
0
0.2
0
25
50
75
100
TEMPERATURE (°C)
Figure 2 Derating Curve
125
0
0
500
1,000
1,500
2,000
2
COPPER AREA (mm )
Figure 3 Area vs. Max Power
2,500
180
160
JUNCTION TO AMBIENT AIR
THERMAL RESISTANCE (°C/W)
140
120
100
80
D = 0.2
D = 0.5
T
A
= 25°C
25mm x 25mm
1oz. FR4
D = 0.1
D = 0.05
Single Pulse
60
40
20
0
0.0001
0.001
0.01
0.1
1
10
PULSE WIDTH (s)
Figure 4 Transient Thermal Impedance
100
1,000
AL5801
Document number: DS35555 Rev. 3 - 2
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AL5801
Typical Performance Characteristics
0.40
0.35
0.30
I
OUT
(mA)
0.25
I
OUT
(A)
0.20
0.15
0.10
0.05
0
0
1
R
EXT
= 11.6
Ω
R
EXT
= 22.7
Ω
R
EXT
= 3.75
Ω
I
bias
= 0.1mA
R
EXT
= 1.6
Ω
400
350
300
250
200
150
100
50
3
0
1
10
R
EXT
(
Ω
)
Figure 6 Output Current vs. R
EXT
100
I
bias
= 0.1mA
2
V
OUT
(V)
Figure 5 Output Current vs. V
OUT
0.5
T
A
= -40
°
C
0.20
T
A
= -40
°
C
0.4
0.15
T
A
= 25
°
C
T
A
= 25
°
C
I
OUT
(A)
I
OUT
(A)
0.3
T
A
= 85
°
C
0.10
T
A
= 85
°
C
0.2
I
bias
= 0.1mA
0.1
R
EXT
= 1.6
Ω
0.05
R
EXT
= 3.75
Ω
I
bias
= 0.1mA
0
0
1
2
3
0
0
V
OUT
(V)
Figure 7 Output Current vs. V
OUT
4
6
8
V
OUT
(V)
Figure 8 Output Current vs. V
OUT
2
10
0.07
0.06
0.05
T
A
= 25
°
C
T
A
= -40
°
C
0.035
0.030
0.025
I
OUT
(A)
0.020
T
A
= 85
°
C
T
A
= -40
°
C
T
A
= 25
°
C
I
OUT
(A)
0.04
T
A
= 85
°
C
0.03
0.02
0.01
0
I
bias
= 0.1mA
R
EXT
= 11.6
Ω
0.015
0.010
0.005
0
0
5
I
bias
= 0.1mA
R
EXT
= 22.7
Ω
0
5
10
15
V
OUT
(V)
Figure 9 Output Current vs. V
OUT
10
15
V
OUT
(V)
Figure 10 Output Current vs. V
OUT
20
AL5801
Document number: DS35555 Rev. 3 - 2
5 of 11
www.diodes.com
July 2012
© Diodes Incorporated
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