INFINEON TLE4241

LED Driver with Adjustable Current
TLE 4241 GM
Features
•
•
•
•
•
•
•
•
•
Adjustable constant output current
Wide input voltage range
Low drop voltage
Open load detection
Overtemperature protection
Short circuit proof
Reverse polarity proof
Wide temperature range: -40 °C < Tj < 150 °C
Very small SMD-Package
P-DSO-8-3, -6, -7, -8, -9
Functional Description
The TLE 4241 GM is an integrated adjustable constant current source. It provides an
output current adjustable via different means (SET, PWM, reference resistor) which is
kept nearly independent from load and supply voltage changes. The IC is designed to
supply LEDs under the severe conditions of automotive applications resulting in constant
brightness and extended LED lifetime. It is provided in the very small P-DSO-8-9
(Micro 8) package. Protection circuits prevent damage to the device in case of overload,
short circuit, reverse polarity and overtemperature. The connected LEDs are protected
against reverse polarity as well as excess voltages up to 45 V. A status output allows
handling of open load and short circuit at the main output.
A PWM input offers the possibility to adjust the LED brightness by pulse width
modulation.
With an implemented high/low current switch the output current level can be reduced e.g.
for brake/tail light application.
The implemented features such as adjustable output current, the high/low current switch
and the provided PWM input make the device well suited for a broad range of LED and
other applications.
Type
Ordering Code
Package
TLE 4241 GM
Q67006-A9644
P-DSO-8-9
Data Sheet
1
Rev. 1.2, 2004-04-13
TLE 4241 GM
Circuit Description
Q
ST
Status
I
Regulation
High
SET
Reference
Voltage
GND
Figure 1
V/I Converter
PWM
Control
Regulation
Low
REF
AEB03003
Block Diagram
An internal reference voltage of typ. 1.20 V supplies the REF pin which is connected to
GND via an external resistor. In the SET = H mode the reference current flowing on the
REF pin is mirrored with an amplification to form the desired output current. The typ.
output current in the SET = H mode calculates:
1.20
I Q, typ /mA = ---------------------- × 487 + 0.1
R REF /kΩ
(1)
The output current is shown as a function of the reference resistance on Page 10 for the
high as well as for the low current mode.
With the PWM input the LED brightness can be regulated via duty cycle. Also PWM = L
sets the TLE 4241 in sleep mode resulting in a very low current consumption of << 1 µA
typ. Due to the high impedance of the PWM input (see timing diagram IPWM versus VPWM
on Page 12) the PWM pin can thus also be used as an Enable input.
Data Sheet
2
Rev. 1.2, 2004-04-13
TLE 4241 GM
GND
1
8
I
ST
2
7
Q
PWM
3
6
REF
SET
4
5
GND
AEP03002
Figure 2
Pin Configuration (top view)
Table 1
Pin Definitions and Functions
Pin No.
Symbol
Function
1
GND
Ground; internally connected to pin 5
2
ST
Status Output; open collector output, connect to external
pull-up resistor (10 kΩ or higher)
3
PWM
Pulse Width Modulation Input; if not needed connect to VI
4
SET
High/Low Current Input; choice of current level
5
GND
Ground; internally connected to pin 1
6
REF
Reference Input; connect to GND via an external resistor to
adjust the output current
7
Q
Output
8
I
Input; block to GND directly at the IC with a 100 nF ceramic
capacitor
Data Sheet
3
Rev. 1.2, 2004-04-13
TLE 4241 GM
Application Information
W
RO
VBatt
TLE 4271
100 nF
22 µF
10 k Ω
WD
VQ
R
ST
µC
PWM
I
TLE 4241G
SET
Q
R REF
LA E67B
OSRAM
AED03098
Figure 3
Application Circuit
Figure 3 shows a typical application with the TLE 4241 GM LED driver. The 3 LEDs are
driven with an adequate supply current adjusted by the resistor RREF. Thus brightness
variations due to forward voltage spread of the LEDs are prevented. The luminosity
spread arising from the LED production process can be compensated via software by an
appropriate duty cycle applied to the PWM pin. Hence selection of the LEDs to forward
voltage as well as to luminosity classes can be spared. The slightly negative temperature
coefficient of the TLE 4241 GM output current protects the LEDs against overtemperature stress if the IC is placed nearby the LEDs.
The voltage drop (VI - VQ) across the TLE 4241 GM is monitored in order to detect an
open load condition indicated at the status output pin ST. In case of open load, the
voltage drop will decrease below the lower status switching threshold Vdr,L. Hence, the
status output ST will be driven low. In normal operation, the voltage drop is above the
upper status threshold Vdr,H, thus the open collector output ST is in high-ohmic state (see
also section Status Output at the Electrical Characteristics).
The function of ST, SET and PWM as well as their timings are shown in Figure 4.
Data Sheet
4
Rev. 1.2, 2004-04-13
TLE 4241 GM
VI
t
VPWM
VPWM, H
VPWM, L
t
VSET
VSET, H
VSET, L
tPWM, OFF
tSET, L
IQ
t
tPWM, ON
tSET, H
mA
47
10
Open Load
VST
t
VSTL
t
AET03339.VSD
Figure 4
Data Sheet
Function and Timing Diagram
5
Rev. 1.2, 2004-04-13
TLE 4241 GM
Table 2
Absolute Maximum Ratings
-40 °C < Tj < 150 °C
Parameter
Symbol
Limit Values
Unit
Remarks
Min.
Max.
VI
II
-42
45
V
–
–
–
mA
internally limited
VQ
IQ
-1
40
V
–
–
–
mA
internally limited
VST
IST
-0.3
40
V
–
–5
5
mA
internally limited
VREF
IREF
-0.3
7
V
–
-2
2
mA
–
Input
Voltage
Current
Output
Voltage
Current
Status Output
Voltage
Current
Reference Input
Voltage
Current
Pulse Width Modulation Input
Voltage
VPWM
-40
40
V
–
Current
–
-1
1
mA
–
VSET
ISET
-40
40
V
–
-1
1
mA
–
Tj
Tstg
-40
150
°C
–
-50
150
°C
–
Rthja
–
105
K/W
High/Low Current Input
Voltage
Current
Temperatures
Junction temperature
Storage temperature
Thermal Resistances
Junction ambient
1)
1) Worst case regarding peak temperature; mounted on PCB 80 × 80 × 1.5 mm , 35 µm Cu, 300 mm2 heat sink
area.
3
Note: Maximum ratings are absolute ratings; exceeding any one of these values may
cause irreversible damage to the integrated circuit.
Data Sheet
6
Rev. 1.2, 2004-04-13
TLE 4241 GM
Table 3
Operating Range
Parameter
Input voltage
Status output voltage
SET voltage
PWM voltage
Junction temperature
Reference Resistor
Data Sheet
Symbol
VI
VST
VSET
VPWM
Tj
RREF
Limit Values
Unit
Remarks
Min.
Max.
4
45
V
–
–
16
V
–
0
40
V
–
0
40
V
–
-40
150
°C
–
7
100
kΩ
SET = H
4.7
18
kΩ
SET = L
7
Rev. 1.2, 2004-04-13
TLE 4241 GM
Table 4
Electrical Characteristics
9 V ≤ VI ≤ 16 V; RREF = 10 kΩ; VPWM ≥ VPWM,H; -40 °C < Tj < 150 °C; all voltages with
respect to ground; positive current defined flowing into pin; unless otherwise specified
Parameter
Symbol
Limit Values
Min.
Typ.
Max.
Unit Test Condition
Current consumption off
mode
IqOFF
–
0.1
2
µA
PWM = L, TJ < 85 °C;
VI ≤ 13.5 V
Current consumption
IqL
IqH
IqL,O
–
5
10
mA
SET = L; VQ = 6 V
–
6
10
mA
SET = H; VQ = 6 V
–
–
10
mA
SET = L; VQ open
IqH,O
–
–
10
mA
SET = H; VQ open
Current consumption
Current consumption
open load
Current consumption
open load
Output
Output current
IQ
Output current
IQ
Current Ratio
IQH/IQL
IQmax
IQmax
Vdr
Output current limit
Output current limit
Drop voltage
6.7
8.4
10
mA
SET = L, VQ = 6 V
–
8.6
–
mA
SET = L, VQ = 4 V
47
58.5
70
mA
SET = H, VQ = 6 V
–
60.0
–
mA
SET = H, VQ = 4 V
6
7
8
–
–
–
83
–
mA
SET = L; RREF = 0 Ω
–
83
–
mA
SET = H; RREF = 0 Ω
–
0.2
0.5
V
SET = L;
IQ = 80% of IQ,nom,L
Drop voltage
Vdr
–
0.3
0.5
V
SET = H;
IQ = 80% of IQ,nom,H
PWM Input
VPWM,H
VPWM,L
IPWM,H
2.0
–
–
V
–
–
–
0.5
V
–
–
220
500
µA
VPWM = 5.0 V
PWM input current
low level
IPWM,L
-10
–
10
µA
VPWM = 0.0 V
Turn on delay time
tPWM,ON
0
5
30
µs
20%/80% IQ, see
Figure 4
PWM high level
PWM low level
PWM input current
high level
Data Sheet
8
Rev. 1.2, 2004-04-13
TLE 4241 GM
Table 4
Electrical Characteristics (cont’d)
9 V ≤ VI ≤ 16 V; RREF = 10 kΩ; VPWM ≥ VPWM,H; -40 °C < Tj < 150 °C; all voltages with
respect to ground; positive current defined flowing into pin; unless otherwise specified
Parameter
Symbol
Limit Values
Min.
Unit Test Condition
Typ.
Max.
tPWM,OFF 0
10
30
VSET,H
VSET,L
ISET,H
2.0
–
–
V
–
–
–
0.5
V
–
–
220
500
µA
VSET = 5.0 V
SET input current
low level
ISET,L
-10
–
10
µA
VSET = 0.0 V
Delay time L -> H
tSET,H
–
–
30
µs
20%/80% IQ, see
Figure 4
Delay time H -> L
tSET,L
–
–
30
µs
20%/80% IQ, see
Figure 4
Vdr,L
0.15
–
–
V
(VI - VQ) decreasing
SET = L
0.15
–
–
V
(VI - VQ) decreasing
SET = H
–
–
0.7
V
(VI - VQ) increasing
SET = L
–
–
0.7
V
(VI - VQ) increasing
SET = H
Turn off delay time
µs
20%/80% IQ, see
Figure 4
SET Input
SET high level
SET low level
SET input current
high level
Status Output
Lower status switching
threshold
Upper status switching
threshold
Vdr,H
Status low voltage
VSTL
–
–
0.4
V
(VI - VQ) < Vdr,L
IST = 1.0 mA
Leakage current
ISTLK
–
–
10
µA
(VI - VQ) > Vdr,H
VST = 5.0 V
Data Sheet
9
Rev. 1.2, 2004-04-13
TLE 4241 GM
Typical Performance Characteristics
Output Current versus
External Resistor, SET = L
Output Current versus
External Resistor, SET = H
AED03333.VSD
100
IQ mA
IQ mA
SET = H
VQ = 6 V
80
16
70
14
60
12
50
10
40
8
30
6
20
4
10
2
0
5
10
0
50 kΩ 100
20
AED03334.VSD
20
SET = L
VQ = 6 V
5
10
50 kΩ 100
20
RREF
RREF
Output Current versus
Supply Voltage, SET = L
Output Current versus
Supply Voltage, SET = H
AED03335.VSD
100
IQ mA
IQ mA
VQ = 6 V
RREF = 10 kΩ
80
14
60
12
50
10
40
8
30
6
20
4
10
2
0
5
10 15 20 25 30
0
V 40
VI
Data Sheet
VQ = 6 V
RREF = 10 kΩ
16
SET = H
70
0
AED03336.VSD
20
SET = L
0
5
10 15 20 25 30
V 40
VI
10
Rev. 1.2, 2004-04-13
TLE 4241 GM
Reference Voltage versus
Junction Temperature
AED03340.VSD
1.25
VREF
V
RREF = 10 kΩ
1.23
1.21
1.19
1.17
1.15
-40
0
40
80
°C
160
Tj
Data Sheet
11
Rev. 1.2, 2004-04-13
TLE 4241 GM
PWM Pin Input Current versus
PWM Voltage
IPWM
PWM Pin Input Current versus
PWM Voltage
AED03332.VSD
2.0
mA
IPWM
1.5
300
1.0
200
0.5
100
0
0
5
10 15 20 25 30
0
V 40
AED03331.VSD
400
µA
0
1
2
3
4
5
6
VPWM
SET Pin Input Current versus
SET Voltage
SET Pin Input Current versus
SET Voltage
AED03338.VSD
2.5
V 8
VPWM
ISET mA
ISET
AED03337.VSD
400
µA
2.0
300
1.5
200
1.0
100
0.5
0
0
5
10 15 20 25 30
0
V 40
Data Sheet
0
1
2
3
4
5
6
V 8
VSET
VSET
12
Rev. 1.2, 2004-04-13
TLE 4241 GM
Package Outlines
1.27
0.1
0.41 +0.1
-0.05
+0.05
-0.01
0.2
C
0.64 ±0.25
0.2 M A C x8
8
5
Index
Marking 1
4
5 -0.21)
8˚ MAX.
4 -0.21)
1.75 MAX.
0.1 MIN.
(1.5)
0.33 ±0.08 x 45˚
6 ±0.2
A
Index Marking (Chamfer)
1)
Does not include plastic or metal protrusion of 0.15 max. per side
GPS09032
Figure 5
P-DSO-8-9 (Plastic Dual Small Outline)
You can find all of our packages, sorts of packing and others in our
Infineon Internet Page “Products”: http://www.infineon.com/products.
Dimensions in mm
SMD = Surface Mounted Device
Data Sheet
13
Rev. 1.2, 2004-04-13
TLE 4241 GM
Revision History
Version Date
Changes
Rev. 1.2 2004-04-13 Page 4, 9: Improved indication and explanation of the open load
detection function.
Data Sheet
14
Rev. 1.2, 2004-04-13
Edition 2004-04-13
Published by Infineon Technologies AG,
St.-Martin-Strasse 53,
81669 München, Germany
© Infineon Technologies AG 2004.
All Rights Reserved.
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circuits, descriptions and charts stated herein.
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