INFINEON TLE4242G

Adjustable LED Driver
TLE 4242 G
Features
•
•
•
•
•
•
•
•
Adjustable constant current up to 500 mA (±5%)
Wide input voltage range up to 42 V
Low drop voltage
Open load detection
Overtemperature protection
Short circuit proof
Reverse polarity proof
Wide temperature range: -40 °C to 150 °C
P-TO263-7-1
Functional Description
The TLE 4242 G is an integrated adjustable constant current source driving loads up to
500 mA. The output current level can be adjusted via an external resistor. The IC is
designed to supply high power LEDs (e.g. Osram Dragon LA W57B) under the severe
conditions of automotive applications resulting in constant brightness and extended LED
lifetime. It is provided in the surface mounted P-TO263-7-1 package. Protection circuits
prevent damage to the device in case of overload, short circuit, reverse polarity and
overheat. The connected LEDs are protected against reverse polarity as well as excess
voltages up to 45 V.
The integrated PWM input of the TLE 4242 G permits LED brightness regulation by
pulse width modulation. Due to the high input impedance of the PWM input the LED
driver can be operated as a protected high side switch.
Type
Ordering Code
Package
TLE 4242 G
Q67006-A9674
P-TO263-7-1
Data Sheet
1
Rev. 1.0, 2004-01-01
TLE 4242 G
Circuit Description
I
PWM
7
1
2
Q
Bias Supply
5
Bandgap
Reference
REF
Comparator
3
ST
Status
Delay
4
GND
Figure 1
6
D
AEB03500.VSD
Block Diagram
An external shunt resistor in the ground path of the connected LEDs is used to sense the
LED current. A regulation loop helds the voltage drop at the shunt resistor on a constant
level of typ. 177 mV. Selecting the shunt resistance permits to adjust the appropriate
constant current level. The typ. output current calculates
V REF
I Q, typ = -----------R REF
(1)
where VREF is the reference voltage with a typical level of 177 mV (see Page 10). The
equation applies in a range of 0.39 Ω ≤ RREF ≤ 1.8 Ω.
The output current is shown as a function of the reference resistance on Page 10. With
the PWM input the LED brightness can be regulated via duty cycle. Also PWM = L sets
the TLE 4242 in sleep mode resulting in a very low current consumption of << 1 µA typ.
Due to the high impedance of the PWM input (see “PWM Pin Input Current versus
PWM Voltage” on Page 11) the PWM pin can thus also be used as an enable input.
Data Sheet
2
Rev. 1.0, 2004-01-01
TLE 4242 G
1
7
Ι
ST
REF
PWM GND
Q
D
AEP01938_4242
Figure 2
Pin Configuration (top view)
Table 1
Pin Definitions and Functions
Pin No.
Symbol
Function
1
I
Input; block to GND directly at the IC with a 100 nF ceramic
capacitor.
2
PWM
Pulse Width Modulation Input; if not needed connect to I
3
ST
Status Output; open collector output, connect to external
pull-up resistor (Rpull-up ≥ 4.7 kΩ).
4
GND
Ground
5
REF
Reference Input; connect to shunt resistor.
6
D
Status Delay; connect to GND via an optional capacitor to
set status reaction delay. Leave open if no ST delay is
needed.
7
Q
Output
Data Sheet
3
Rev. 1.0, 2004-01-01
TLE 4242 G
Application Information
VBAT
I
RO
TLE 4269 G
µC
SI
Q
RADJ
GND
D
100
nF
10
µF
10 kΩ
ST
PWM
I
Q
TLE 4242 G
LED
Dragon
REF
GND
D
47 nF
0.47 Ω
0.25 W
RREF
AEA03499.VSD
Figure 3
Application Circuit
Figure 3 shows a typical application with the TLE 4242 G 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 minimum supply voltage
calculates as the sum of the LED forward voltages, the TLE 4242 G drop voltage (max.
0.7 V at a LED current of 300 mA) and the max. voltage drop at the shunt resistor RREF
of max. 185 mV.
The status output of the LED driver (ST) detects an open load condition enabling to
supervise correct LED function. A LED failure is detected if the voltage drop at the shunt
resistor RREF falls below typ. 25 mV. In this case the status output pin ST is set low after
a delay time adjustable via an optional capacitor connected to the pin D.
Data Sheet
4
Rev. 1.0, 2004-01-01
TLE 4242 G
The functionality of the ST and PWM as well as their timings are shown in Figure 4. The
Status delay can be adjusted via the capacitor connected to the timing Pin D. The delay
time scales in linear way with the capacitance CD:
CD
- × 10 ms
t STHL,typ = -------------47 nF
CD
- × 10 µ s
t STLH,typ = --------------
(2)
47 nF
VI
Open
Load
t
VPWM
VPWM, H
VPWM, L
IQ
tPWM, ON
t
tPWM, OFF
mA
256
tSTHL
VD
t
VUD
VLD
t
VST
VSTL
t
AET03505.VSD
Figure 4
Data Sheet
Function and Timing Diagram
5
Rev. 1.0, 2004-01-01
TLE 4242 G
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
–
VD
-0.3
7
V
–
VREF
IREF
-1
16
V
–
-2
2
mA
–
Input
Voltage
Current
Output
Voltage
Current
Status Output
Voltage
Current
Status Delay
Voltage
Reference Input
Voltage
Current
Pulse Width Modulation Input
Voltage
VPWM
-40
40
V
–
Current
–
-1
1
mA
–
Tj
Tstg
-40
150
°C
–
-50
150
°C
–
Rthja
–
78
K/W
Footprint only1)
–
52
K/W
300mm2 heat sink area
–
39
K/W
600mm2 heat sink area
–
3
K/W
–
Temperatures
Junction temperature
Storage temperature
Thermal Resistances
Junction ambient
Junction case
Rthjc
1) Worst case regarding peak temperature; mounted on PCB FR4, 80 × 80 × 1.5 mm3, 35 µm Cu.
Note: Maximum ratings are absolute ratings; exceeding any one of these values may
cause irreversible damage to the integrated circuit.
Data Sheet
6
Rev. 1.0, 2004-01-01
TLE 4242 G
Table 3
Operating Range
Parameter
Input voltage
Status output voltage
Status Delay
capacitance
PWM voltage
Junction temperature
Reference resistor
Data Sheet
Symbol
Limit Values
Unit
Remarks
Min.
Max.
VI
VST
CD
4.5
42
V
–
–
16
V
–
0
2.2
µF
–
VPWM
Tj
RREF
0
40
V
–
-40
150
°C
–
0
1.8
Ω
–
7
Rev. 1.0, 2004-01-01
TLE 4242 G
Table 4
Electrical Characteristics
VI = 13.5 V; RREF = 0.47 Ω; 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
Unit Test Condition
Min.
Typ.
Max.
Current consumption IqOFF
off mode
–
0.1
2
µA
PWM = L,
Tj < 85 °C
Current consumption IqL
–
12
22
mA
VQ = 6.6 V
357
376
395
mA
168
177
185
mA
431
454
476
mA
357
376
395
mA
IQmax
Vdr
–
600
–
mA
–
0.35
0.7
V
VQ - VREF1) = 6.6 V
VQ - VREF = 6.6 V;
RREF = 1.0 Ω
VQ - VREF = 6.6 V;
RREF = 0.39 Ω
5.4 V ≤ VQ - VREF ≤ 7.8 V;
9 V ≤ VI ≤ 16 V
RREF = 0 Ω
IQ = 300 mA
VPWM,H
VPWM,L
IPWM,H
2.6
–
–
V
–
–
–
0.7
V
–
–
220
500
µA
VPWM = 5.0 V
PWM input current
low level
IPWM,L
-1
–
1
µA
VPWM = 0.0 V
Turn on delay time
tPWM,ON
0
15
40
µs
70% of IQnom, see
Figure 4
Turn off delay time
tPWM,OFF 0
15
40
µs
30% of IQnom, see
Figure 4
Output
Output current
Output current limit
Drop voltage
IQ
PWM Input
PWM high level
PWM low level
PWM input current
high level
Data Sheet
8
Rev. 1.0, 2004-01-01
TLE 4242 G
Table 4
Electrical Characteristics (cont’d)
VI = 13.5 V; RREF = 0.47 Ω; 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
Unit Test Condition
Min.
Typ.
Max.
VREF
IREF
168
177
185
mV
0.39 < RREF < 1.0 Ω
-1
0.1
1
µA
VREF = 180 mV
Lower status
switching threshold
VIQL
15
25
–
mV
ST = L
Upper status
switching threshold
VIQH
–
30
40
mV
ST = H
Status low voltage
VSTL
ISTLK
–
–
0.4
V
–
–
5
µA
IST = 1.5 mA
VST = 5.0 V
Status reaction delay tSTHL
6
10
14
ms
Status release delay tSTLH
–
10
20
µs
Reference
Reference Voltage
Reference Input
Current
Status Output
Leakage current
Status Delay
CD = 47 nF, ST H → L
CD = 47 nF, ST L → H
1) VQ - VREF equals the forward voltage sum of the connected LEDs, see Figure 3.
Data Sheet
9
Rev. 1.0, 2004-01-01
TLE 4242 G
Typical Performance Characteristics
Output Current versus
External Resistor
IQ
0.39 0.47
600
mA
Reference Voltage versus
Junction Temperature
AED03503.VSD
VQ = 6.6 V
VREF
500
AED03506.VSD
185
mV
180
400
175
300
170
200
165
100
0
0.2
0.5
1.0
160
-40
Ω 2.0
0
40
80
°C
160
Tj
RREF
Output Current versus
Supply Voltage
IQ
AED03504.VSD
600
mA
VQ = 6.6 V
RREF = 0.47 Ω
500
400
300
200
100
0
0
5
10 15 20 25 30
V 40
VI
Data Sheet
10
Rev. 1.0, 2004-01-01
TLE 4242 G
PWM Pin Input Current versus
PWM Voltage
IPWM
PWM Pin Input Current versus
PWM Voltage
AED03502.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
0
1
2
3
4
5
6
7 V8
VPWM
VPWM
Data Sheet
AED03501.VSD
400
µA
11
Rev. 1.0, 2004-01-01
TLE 4242 G
Package Outlines
10 ±0.2
4.4
9.8 ±0.15
1.27 ±0.1
B
0.1
0.05
2.4
2.7 ±0.3
4.7 ±0.5
8 1)
9.25 ±0.2
(15)
1±0.3
A
8.5 1)
0...0.15
7x0.6 ±0.1
0.5 ±0.1
6x1.27
8˚ max.
0.25
1)
M
A B
0.1
Typical
All metal surfaces tin plated, except area of cut.
GPT09114
Figure 5
P-TO263-7-1 (Plastic Transistor Single 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
12
Rev. 1.0, 2004-01-01
Edition 2004-01-01
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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