Automotive Power
Datasheet
Rev. 1.0, 2011-05-27
TLD5045EJ
700mA High Integration - DC/DC Step-
Down Converter
Infineon® Power LED Driver
Datasheet 2 Rev. 1.0, 2011-05-27
TLD5045EJ
Table of Contents
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Pin Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2 Pin Definitions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 General Product Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2 Functional Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.3 Thermal Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 General Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2 Power Supply Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6 Enable, Dimming Function and Thermal Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.2 Electrical Characteristics Enable, Bias, Dimming Function and Thermal Protection . . . . . . . . . . . . . 12
6.2.1 PWM Dimming with µC connected to TLD5045 PWMI pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.2.2 Internal PWM dimming Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.3 Overtemperature Protection of the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7 Open Load Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.2 Electrical Characteristics: Open Load Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.3 Open Load Diagnosis in different Application Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.3.1 Light module application without µC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.4 Application with µC connected to TLD5045 IC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8 Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.1 Output Peak Current Adjustment via RSET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.2 Switching Frequency Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
8.3 TLD5045 in different LED Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8.3.1 TLD5045 in a Body Control Module (BCM) with µC Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8.3.2 Decentralized Light Module Application - DLM (Input configuration 1) . . . . . . . . . . . . . . . . . . . . . . 23
8.3.3 Decentralized Light Module Application - DLM (Input configuration 2) . . . . . . . . . . . . . . . . . . . . . . 24
8.3.4 Decentralized Light Module Application - DLM (Input configuration 3) . . . . . . . . . . . . . . . . . . . . . . 25
9 Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10 Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table of Contents
PG-DSO-8 EP
Type Package Marking
TLD5045EJ PG-DSO-8 EP TLD5045
Datasheet 3 Rev. 1.0, 2011-05-27
700mA High Integration - DC/DC Step-Down Converter TLD5045EJ
1Overview
• Constant Current Generation
• Wide Input Voltage Range from 5V to 40V
• Peak Current Regulation
• Very low current consumption (<2uA) in Sleep Mode
• Integrated power transistor with low saturation voltage
• Integrated fast freewheeling diode
• Integrated load current sense resistor
• Integrated status pull down transistor
• Overtemperature Protection
• Switching frequency (typ. 200kHz) adjustable via external RC network
• External PWM Dimming Input
• Integrated PWM Dimming Engine
• Analog Dimming (output current adjustable via external low power resistor and possibility to connect PTC
resistor for LED protection during overtemperature conditions)
• Stable switching frequency due to fix OFF-time concept with VREC (supply voltage) feedforward
• Under- and Overvoltage shutdown with hysteresis
• Small thermally enhanced exposed heatslug SMD package
• Automotive AEC Qualified
• Green Product (RoHS) Compliant
Description
The TLD5045 is a highly integrated smart LED buck controller with built in protection functions. The main function
of this device is to drive single or multiple series connected LEDs efficiently from a voltage source higher than the
LED forward voltage by regulating a constant LED current. The constant current regulation is especially beneficial
for LED color accuracy and long LED lifetime. The built in freewheeling diode and switching transistor with current
sense requires less external components and saves system costs. High flexibility is achieved by placing low power
resistors to adjust output currents up to 700mA and the regulator switching frequency (typ. 200kHz). An integrated
PWM dimming engine provides a LED dimming function by placing a simple RC network to GND. This feature is
dedicated for decentralized light modules without micro controller involvement. In addition to that an integrated
status pull down transistor can be used to simulate a minimum current flow for decentralized modules to avoid a
wrong open load detection by a highside switch located in the body control module (BCM).
Applications
• Automotive LED driven Exterior Lighting: Brake, Tail, CHMSL, Daytime Running Light, Position Light
• Automotive LED driven Interior Lighting: Reading Light, Dome Light, Display Backlighting
Datasheet 4 Rev. 1.0, 2011-05-27
TLD5045EJ
Block Diagram
2 Block Diagram
The TLD5045 regulates the LED current by monitoring the load current (Peak Current Measurement) through the
internal switch cycle by cycle. When the current through the switch reaches the threshold Ipeak the switch is shut-
OFF and it is kept OFF for a time equal to tOFF. Both Ipeak and tOFF can be fixed through few external components.
The peak current Ipeak is fixed by a resistor connected to the SET pin while the tOFF is fixed by RC network. As tOFF
is fixed and the duty cycle depends on VREC, the frequency depends on VREC as well. Refer to Chapter 8.2 for the
evaluation of the switching frequency.
Figure 1 Block Diagram TLD5045
1
5
3
2
8
7
6
GND
VREC
Logic
Power
Switch
FREQ
SW
Internal
Supply
EN
Thermal
Protection
UV+OV
Lockout
SET
PWMI
ST
Power-
Switch Driver
Open Load
Detection
Peak Current
Measurement
ON/OFF
Logic
Peak Current
Adjustment
4
OFF-Time
Control
internal
PWM
Generation
TLD5045EJ
Pin Configuration
Datasheet 5 Rev. 1.0, 2011-05-27
3 Pin Configuration
3.1 Pin Assignment
Figure 2 Pin Configuration TLD5045
3.2 Pin Definitions and Functions
Pin Symbol Function
1VREC Voltage Recirculation Output and Internal Supply Input;
This pin is the supply pin of the IC (see block diagram). Furthermore the cathode of the
integrated fast freewheeling diode is connected to this pin as well.
2ST Status Output;
Open collector diagnostic output to indicate an open load failure.
Refer to Chapter 7 for more details.
3EN Enable;
Apply logic HIGH signal to enable the device
4SET SET Input;
Connect a low power resistor to adjust the output current.
5PWMI PWM Input;
PWM signal for dimming LEDs. Connect external R and C combination to achieve an auto
PWM-dimming function with defined frequency and duty cycle.
1) internal PWM dimming function (external RC connected to GND)
2) external PWM dimming function (µC is controlling this pin)
Refer to Chapter 6 for more details.
6FREQ FREQuency Select Input;
Connect external Resistor and Capacitor to GND to set the OFF-time of the switching
frequency.
7GND Ground;
Connect to system ground.
ST GND
EN FREQ
SW
5
6
4
3
2 7
1 8
SET
TLD5045
VREC
PWMI
EP
Datasheet 6 Rev. 1.0, 2011-05-27
TLD5045EJ
Pin Configuration
8SW Integrated Power-Switch Output;
Collector of the integrated NPN-power transistor.
EP Exposed Pad;
Connect to external heatspreading copper area with electrically GND (e.g. inner GND layer of
the PCB via thermal vias)
Pin Symbol Function
TLD5045EJ
General Product Characteristics
Datasheet 7 Rev. 1.0, 2011-05-27
4 General Product Characteristics
4.1 Absolute Maximum Ratings
Note: Stresses above the ones listed here may cause permanent damage to the device. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Note: Integrated protection functions are designed to prevent IC destruction under fault conditions described in the
data sheet. Fault conditions are considered as “outside” normal operating range. Protection functions are
not designed for continuous repetitive operation.
Absolute Maximum Ratings1)
Tj = -40 °C to +150 °C; all voltages with respect to ground (unless otherwise specified)
1) Not subject to production test, specified by design.
Pos. Parameter Symbol Limit Values Unit Conditions
Min. Max.
Voltages
4.1.1 VREC (Pin 1)
Recirculation and Supply Input
VREC -0.3 45 V –
4.1.2 ST (Pin 2)
Diagnostic Status Output Voltage
VST -0.3 45 V –
4.1.3 ST (Pin 2)
Diagnostic Status Current
IST –150mA–
4.1.4 EN (Pin 3)
Enable Input Voltage
VEN -0.3 45 V –
4.1.5 SET (Pin 4)
Peak Current Adjust Input Voltage
VSET -0.3 6 V –
4.1.6 PWMI (Pin 5)
PWM Input Voltage
VPWMI -0.3 6 V –
4.1.7 FREQ (Pin 6)
OFF-time Adjustment Input
VFREQ -0.3 6 V –
4.1.8 SW (Pin 8)
Switch Output
VSW -0.3 45 V –
Temperatures
4.1.9 Junction Temperature Tj-40 150 °C–
4.1.10 Storage Temperature Tstg -55 150 °C–
ESD Susceptibility
4.1.11 ESD Resistivity all Pins to GND VESD,HBM -2 2 kV HBM 2)
2) ESD susceptibility HBM according to EIA/JESD 22-A 114B
Datasheet 8 Rev. 1.0, 2011-05-27
TLD5045EJ
General Product Characteristics
4.2 Functional Range
Note: Within the functional range the IC operates as described in the circuit description. The electrical
characteristics are specified within the conditions given in the related electrical characteristics table.
4.3 Thermal Resistance
Note: This thermal data was generated in accordance with JEDEC JESD51 standards.
For more information, go to www.jedec.org.
Pos. Parameter Symbol Limit Values Unit Conditions
Min. Max.
4.2.1 Extended Supply Voltage VREC 540
1)
1) Not subject to production test, specified by design.
parameter
deviations possible
4.2.1 Nominal Supply Voltage Range VREC 836V–
4.2.2 Output current range IOUT 100 700 mA –
4.2.3 Switching Frequency fSW 50 3001) kHz Tj = 25°C to 150°C
4.2.4 Junction Temperature Tj-40 150 °C–
Pos. Parameter Symbol Limit Values Unit Conditions
Min. Typ. Max.
4.3.1 Junction to Case RthJ-case –10–K/W
1) 2)
1) Not subject to production test, specified by design.
2) Specified RthJ-case value is simulated at natural convection on a cold plate setup (all pins and the exposed Pad are fixed to
ambient temperature). Ta=25°C, Power Switch and freewheeling diode are dissipating 1W.
4.3.2 Junction to Ambient (2s2p) RthJA –40–K/W
1) 3)
3) Specified RthJA value is according to Jedec JESD51-2,-7 at natural convection on FR4 2s2p board; The Product
(Chip+Package) was simulated on a 76.2 x 114.3 x 1.5 mm board with 2 inner copper layers (2 x 70µm Cu, 2 x 35µm Cu).
According to JESD51-5 a thermal via array under the exposed pad contacted the first inner copper layer. Ta=25°C, Power
Switch and freewheeling diode are dissipating 1W.
TLD5045EJ
Electrical Characteristics
Datasheet 9 Rev. 1.0, 2011-05-27
5 Electrical Characteristics
5.1 General Parameters
Electrical Characteristics: Buck Regulator
VREC = 8 V to 36 V, Tj = -40 °C to +150 °C, all voltages with respect to ground (unless otherwise specified)
Pos. Parameter Symbol Limit Values Unit Conditions
Min. Typ. Max.
5.1.1 Voltage Drop over Power
Transistor
VDrop,100 –0.8– VIpeak=100mA
5.1.2 Voltage Drop over Power
Transistor
VDrop,700 –1.4– VIpeak=700mA
5.1.3 Freewheeling diode forward
voltage
Vfw,100 –0.8– VIpeak=100mA
5.1.4 Freewheeling diode forward
voltage
Vfw,700 –1.4– VIpeak=700mA
5.1.5 Peak over current limit Ipeak_lim –1.4– A–
5.1.6 Peak current accuracy Ipeak_acc 450 500 550 mA VREC = 12V
VEN = 5V
VLED = 7.2V
RSET = 14kΩ
LSW = 220µH
fSW = 200kHz
5.1.7 Input under voltage shutdown
threshold
VREC,UVOFF –– 5 V
VEN = 5V
VREC decreasing; see
Figure 3
5.1.8 Input voltage startup threshold VREC,UVON –– 6 V
VEN = 5V
VREC increasing; see
Figure 3
5.1.9 Input over voltage shutdown
threshold
VREC,OVOFF 40.5 – – V VEN = 5V
VREC increasing; see
Figure 3
5.1.10 Input over voltage startup threshold VREC,OV 40 – – V VEN = 5V
VREC decreasing; see
Figure 3
5.1.11 Switch ON delay tdON – 400 600 ns 1)–
1) The minimum switching ON time tON must be greater than tdON + tdOFF
5.1.12 Switch OFF delay tdOFF –500850ns
1)–
5.1.13 Reference Voltage at SET pin VSET 1.16 1.225 1.29 V –
5.1.14 Pull up current for FREQ pin IFREQ 5– – mAVFREQ=0V
5.1.15 Oscillator switch off threshold VFREQ,HIGH –3.2– V–
5.1.16 Oscillator switch on threshold VFREQ,LOW –1.2– V–
Datasheet 10 Rev. 1.0, 2011-05-27
TLD5045EJ
5.2 Power Supply Monitoring
Over- and Undervoltage shutdown
If the supply voltage VREC drops below the Input under voltage threshold voltage VREC,UVOFF, the power stage is
switched OFF and the device is in normal consumption mode (Iq,ON).
If VREC rises again and reaches the Input under voltage startup threshold VREC,UVON the power stage is restarted
and the device is back to normal operation mode.
Same behavior applies to overvoltage.
The internal status transistor is switching off during an overvoltage or undervoltage event on VREC.
A detailed description of the under- and overvoltage behavior is displayed in Figure 3 below.
Figure 3 Over- and Undervoltage Protection
VSW
V
REC,UVoff
V
REC,UVon
V
REC,UVhyst
t
t
ILED
t
VREC
V
REC,OVhyst
V
REC,OVon
V
REC,OVoff
I
set
ST
t
ST pull-
down ON ST pull-down transistor OFFST pull-down transistor OFF ST pull-
down ON
ST pull-
down ON
TLD5045EJ
Enable, Dimming Function and Thermal Protection
Datasheet 11 Rev. 1.0, 2011-05-27
6 Enable, Dimming Function and Thermal Protection
6.1 Description
Enable function:
A logic high signal on the EN pin turns the device on. A logic low signal on enable pin EN brings the device in sleep
mode. The current consumption is typ. 0.1µA in this case. The EN pin has an internal pull down resistor which
ensures that the IC is in sleep mode and the power stage is switched off in case the pin EN is externally not
connected.
Dimming function:
The PWMI pin combines two functions:
1) PWM dimmming via a µC (3.3Vand 5V µC)
2) Integrated PWM dimming engine for standalone solutions in decentralized light module (frequency and duty
cycle adjustable via external R,C network)
A detailed description of the PWMI pin is displayed in Figure 4 below.
Figure 4 PWMI Pin description
PWMI ON ÆDC=100%
V
PWMI
PWMI OFF ÆDC=0%
t
SW-
ON SW - OFF SW-
ON SW - OFF SW-
ON SW - OFF SW-
ON SW - OFF
Internal PWM
V
PWMI,OFF
V
PWMI,ON
Datasheet 12 Rev. 1.0, 2011-05-27
TLD5045EJ
Enable, Dimming Function and Thermal Protection
6.2 Electrical Characteristics Enable, Bias, Dimming Function and Thermal
Protection
Electrical Characteristics: Enable, Bias, Dimming Function and Thermal Protection
VREC = 8 V to 36 V, Tj = -40 °C to +150 °C, all voltages with respect to ground (unless otherwise specified)
Pos. Parameter Symbol Limit Values Unit Conditions
Min. Typ. Max.
6.2.1 Current Consumption,
sleep mode
Iq,OFF –0.12µAVEN = 0V;
VREC = 16V
6.2.2 Current Consumption,
active mode (Open Load)
Iq,ON ––5mAVEN = 5.0V;
Ipeak = 0mA (open load);
VREC = 16V
6.2.3 Current Consumption,
active mode
Iq,ON ––10mAVEN = 5.0V;
Ipeak = 700mA
VREC = 16V
6.2.4 EN
Turn On Threshold
VEN,ON 2.8 – – V –
6.2.5 EN
Turn Off Threshold
VEN,OFF ––0.8V–
6.2.6 EN
high input current
IEN,hi –100–µAVEN = 5V
6.2.7 EN
low input current
IEN,lo 0–20µAVEN = 0.5V
6.2.8 PWMI
Turn On Threshold
VPWMI,ON –1–Vsee Figure 4
6.2.9 PWMI
Turn Off Threshold
VPWMI,OFF –2–Vsee Figure 4
6.2.10 PWMI
source current
IPWMI –250–µA
Rset = 10kΩ
VPWMI = 0.5V;
6.2.11 Over temperature shutdown Tj,sd 150 175 – °C 1)
1) Specified by design. Not subject to production test.
6.2.12 Over temperature shutdown
hysteresis
Tj,sd_hyst –15–K
1)
TLD5045EJ
Enable, Dimming Function and Thermal Protection
Datasheet 13 Rev. 1.0, 2011-05-27
6.2.1 PWM Dimming with µC connected to TLD5045 PWMI pin
The PWMI pin can be used for PWM dimming. It is a commonly practiced dimming method to prevent color shift
in LED light applications.
Figure 5 Timing Diagram for LED Dimming with µC
V
PWMI
V
PWMI,OFF
I
peak
V
PWMI,ON
t
t
T
PWMI
t
OFF
SW - ONSW - OFF SW - OFF SW - ON SW - OFF
Datasheet 14 Rev. 1.0, 2011-05-27
TLD5045EJ
Enable, Dimming Function and Thermal Protection
6.2.2 Internal PWM dimming Function
The TLD5045 has an integrated PWM dimming engine. Via an external RPWM and CPWM network it is possible to
achieve a PWM LED current waveform. The duty cycle and dimming frequency is depending on the size of the
external components (see formula in Figure 7). This feature is specially designed to achieve a stand alone PWM
dimming function without the usage of micro controllers or external logic. This allows a flexible and cost effective
usage of the device in a decentralized light module application (refer to application drawing Figure 15).
The advantage of a PWM dimming (to reduce the LED load current) is the change of light intensity only, at constant
light color.
With an external RC network a PWM programming between 100Hz and 1200Hz and Duty Cycles between 4%
and max. 20%. is possible. Figure 6 displays the external components corresponding to the desired PWM
frequency and duty cycle.
The following setup applies for the table displayed in Figure 6: VREC=12V, VLED=7.2V, LSW=220µH, RSET=14kΩ.
Figure 6 RPWMI and CPWMI versus fPWMI and DC
R
PWMI
C
PWMI
f
PWMI
DC
216kΩ64nF 100Hz 4%
216kΩ32nF 200Hz 4%
216kΩ21nF 300Hz 4%
216kΩ16nF 400Hz 4%
87kΩ150nF 100Hz 10%
87kΩ75nF 200Hz 10%
87kΩ50nF 300Hz 10%
87kΩ37nF 400Hz 10%
44kΩ265nF 100Hz 20%
44kΩ132nF 200Hz 20%
44kΩ88nF 300Hz 20%
44kΩ
66nF 400Hz 20%
TLD5045EJ
Enable, Dimming Function and Thermal Protection
Datasheet 15 Rev. 1.0, 2011-05-27
6.3 Overtemperature Protection of the Device
A temperature sensor at the power stage causes the overheated device to switch OFF to prevent destruction.
During over temperature condition the internal ST transistor is switched OFF. Due to the autorestart function of
the device the status signal will toggle accordingly. The timing of this pattern is dependant on the thermal capability
of the application and can be used to distinguish between open load error and overtemperature condition. More
details on the overtemperature behavior is displayed in Figure 7 below.
Figure 7 Overtemperature Behavior
V
SW
t
I
LED
t
ΔΤ
V
EN
t
H
L
T
j
t
Ta
TjSD
TjSO
Ipeak
ST
t
ST pull-down transistor ON
ST pull-
down OFF
ST
OFF
ST
ON
ST
OFF
ST
ON
ST
OFF
ST
ON
ST
OFF
Datasheet 16 Rev. 1.0, 2011-05-27
TLD5045EJ
Open Load Diagnosis
7 Open Load Diagnosis
7.1 Description
The TLD5045 has an integrated open load during ON diagnosis. During normal operation the ST pin (open
collector output) is pulled to GND (internal transistor is ON). The open load detection is realized by monitoring the
switching behavior at the SW pin. During an open load event the integrated power stage at the SW pin will be
statically turned ON. If the output stage is turned ON for more than the open load diagnosis delay time (tOL) an
open load condition is detected. An open load event will switch OFF the internal transistor. If a µC is connected to
the ST pin an external pull up resistor should be placed to achieve a logic HIGH level for the proper open load
error signalling reporting. For a timing diagram on the functionality of the open load diagnosis please refer to figure
Figure 8 and Figure 9.
7.2 Electrical Characteristics: Open Load Diagnosis
Electrical Characteristics: Open Load Diagnosis
VREC = 8 V to 36 V, Tj = -40 °C to +150 °C, all voltages with respect to ground (unless otherwise specified)
Pos. Parameter Symbol Limit Values Unit Conditions
Min. Typ. Max.
7.2.1 Open Load diagnosis
DelayTime
tOL 20 – – µs –
7.2.2 Voltage Drop over internal
ST transistor
VDrop,ST –0.3–VI
ST=150mA
TLD5045EJ
Open Load Diagnosis
Datasheet 17 Rev. 1.0, 2011-05-27
7.3 Open Load Diagnosis in different Application Conditions
7.3.1 Light module application without µC
Most of the time, the open load diagnosis of the whole light module is done via the current sense of the driver IC
(e.g. PROFET) located in the light control module (or BCM module). See Figure 15 for a simplified application
schematic. The light module needs to sink a specified minimum current (e.g. 100mA) to indicate normal operation.
To guarantee this minimum current also under light load conditions (e.g. high efficiency LED bin at high supply
voltages = min. load current required) system designers often have to place resistors in parallel to the application
circuit (see Resistors connected to supply lines in Figure 15). When using such resistors connected between VS
and GND, an open LED diagnosis is not possible anymore. To overcome this issue an internal transistor (open
collector) is connected to the ST pin of the TLD5045. During normal operation the ST pin is LOW and a minimum
module current can be guaranteed.
As soon as an open load occurs the internal ST transistor switches off. Due to this, the current on the VREC pin
decreases below the open load detection threshold of the driver IC located in the light control module.
Note: Open Load is only detected during the ON cycle of the switching transistor. During the OFF state the ST
signal displays what was detected in the previous ON state.
Figure 8 Open Load Diagnosis using Internal PWM Mode
Datasheet 18 Rev. 1.0, 2011-05-27
TLD5045EJ
Open Load Diagnosis
7.4 Application with µC connected to TLD5045 IC
The ST pin can be connected directly to a µC input. During an open load condition the ST transistor is OFF. An
external pull up resistor connected to VDD is required to signal a logic high signal on the ST pin during an open
load error. Please consider that this diagnosis functionality is only active if the device is in active mode (HIGH
potential at the EN pin).
Refer to application drawing Figure 14.
Figure 9 Open Load diagnosis via µC connected to ST pin
Open Load
Event
V
SW
ST t
OL
Open Load
t
t
t
t
T
PWMI
V
EN
t
High
Low
SW - ON
SW - OFF SW - OFF
SW - ON
SW - OFF
V
PWMI,OFF
V
PWMI,ON
ST pull -down transistor ON
ST pull-down transistor OFF
V
PWMI
High - z
TLD5045EJ
Application Information
Datasheet 19 Rev. 1.0, 2011-05-27
8 Application Information
Note: The following information is given as a hint for the implementation of the device only and shall not be
regarded as a description or warranty of a certain functionality, condition or quality of the device.
8.1 Output Peak Current Adjustment via RSET
The external resistor RSET is used to adjust the peak current of the regulator. Maximum achievable peak current
is 700mA and minimum achievable peak current is 100mA. The SET pin provides an internally fixed voltage level
at typ.: 1.225V. Out of this considerations the equation is:
Ipeak = (1.225V / RSET) * 5710
The factor 5710 is derived from following considerations:
• Ipeak, max = 700mA (RSET = 10kΩ)
• Ipeak,min = 100mA (RSET = 70kΩ)
Internal comperator voltage at SET pin = 1.225V.
The circuitry behind the SET pin is adjusting higher peak currents with lower RSET values.
The RSET value should be in the range from 10kΩ to 70kΩ to achieve the requested peak current range.
The following setup applies for the table displayed in Figure 10: VREC=12V, VLED=7.2V, LSW=220µH.
Figure 10 RSET Resistor Selection
I
PEAK
[mA] R
SET
[kΩ]
100
200
300
400
500
600
700
70
35
23
18
14
12
10
Datasheet 20 Rev. 1.0, 2011-05-27
TLD5045EJ
Application Information
8.2 Switching Frequency Determination
With the external RFREQ, CFREQ and RCOMP network, it is possible to adjust the switching frequency of the regulator.
To ensure a stable frequency over a broad range of input voltage VREC an external resistor RCOMP can be used.
The following setup applies for the table displayed in Figure 12: VREC=12V, VLED=7.2V, LSW=220µH, RSET=14kΩ.
Figure 11 Setting tOFF Time of Regulator with External RFREQ, CFREQ Network
Figure 12 RFREQ, CFREQ versus fSW Table
7
GND
6
FREQ
TLD5045
R
FREQ
C
FREQ
1
VREC R
COMP
Rcomp Rfreq Cfreq fsw toff
255.8kΩ17.1kΩ220pF 50kHz 6.47μs
115.8kΩ7.7kΩ220pF 100kHz 3.19μs
69.7kΩ4.6kΩ220pF 150kHz 2.12μs
46.8kΩ3.1kΩ220pF 200kHz 1.59μs
72.8kΩ4.9kΩ100pF 250kHz 1.27μs
52.7kΩ3.5kΩ
100pF 300kHz
1.06μs
TLD5045EJ
Application Information
Datasheet 21 Rev. 1.0, 2011-05-27
Figure 13 Theoretical Operating Waveforms
V
EN
t
down
t
t
t
t
High
Low
V
FREQ
I
LED
V
SW
V
FREQ,high
V
FREQ,low
I
set
=I
peak
V
REC
+V
fw
V
drop
Transistor Diode TDiode TDiode TDiode TDiode
t
up
t
on
t
off
I
min
I
ripple
Datasheet 22 Rev. 1.0, 2011-05-27
TLD5045EJ
Application Information
8.3 TLD5045 in different LED Applications
8.3.1 TLD5045 in a Body Control Module (BCM) with µC Interface
Figure 14 provides a simplified application with two high brightness LEDs in series. A µC is controlling the EN pin
to put the device into sleep/active mode. Also the PWMI pin can be directly controlled via a µC port if PWM
dimming of the LED current is required. The open load ST pin monitors the load condition of the application and
gives feedback to the µC. An external pull up resistor is recommended to achieve a logic HIGH signal during an
open load error (internal status transistor is switched OFF and the ST pin is high ohmic an external pull up resistor
ensures a logic HIGH signal).
The external low power resistor RSET is used to set the required peak current for the LED load (refer to Figure 10
for more details).
To set the desired switching frequency of the buck regulator the external RFREQ and CFREQ network must be
connected to GND (reference values are given in Figure 12).
Figure 14 Simplified Application Diagram TLD5045
Note: This is a very simplified example of an application circuit. The function must be verified in the real application
SW
GND
FREQ
PWMI
ST
EN
VREC
5
6
7
81
4
3
2
TLD5045
L
SW
C
FREQ
R
FREQ
R
SET
C
REC
Vs = 5V to 40V
PWM dimming via µC
open load status
connected to µC
I
LED
SET
connect to µC pin
V
DD
R
COMP
V
REC
R
EMC
R
ST
TLD5045EJ
Application Information
Datasheet 23 Rev. 1.0, 2011-05-27
8.3.2 Decentralized Light Module Application - DLM (Input configuration 1)
The connection between the Body Control Module (BCM) and the Decentralized Light Module is realized via one
supply line and one GND connection.
The supply line could change between two different operation modes:
1) Light Function 1 - Daytime Running Light (DRL) mode: If the supply line is permanently ON, the DRL
application which requires higher LED current (e.g. 400mA) is active. The proper RSET resistor should be placed
to achieve the desired load current (e.g 18kΩ).
2) Light Function 2 - Position Light (PL) mode: During a PWM signal (e.g. 200Hz) on the supply line the mean
LED current is reduced to a lower level (e.g. 50mA) and the application is entering into PL mode. The enable pin
of the TLD5045 is a high voltage pin (max. 45V) and can be directly connected via a resistor REN before the reverse
polarity protection diode of the module to achieve a fast capture of the PWM signal. The PWMI pin is connected
to GND (inverse logic = ON).
To simulate a module current during light load conditions, the ST pin can be connected via a resistor to the supply
voltage line. (refer to Chapter 7 for a detailed description of the ST behavior)
For a decentralized solution without micro controller involvement the possibility to connect a PTC resistor at the
SET pin is a cost effective solution to protect the LED load from thermal destruction.
Figure 15 Application Diagram of Decentralized Light Module without µC (input config 1)
This is a very simplified example of an application circuit. The function must be verified in the real application
SW
GND
FREQ
SET
ST
PWMI
VREC
4
6
7
81
3
5
2
TLD5045
C
FREQ
R
FREQ
R
SET
I
ST,PD
Vbat
BCM - module
Wire Harness
Inductance
Light Function 1
(e.g. DRL)
GND
I
Open_load
I
LED
Decentralized Light Module
EN
C
REC
R
PTC
R
COMP
V
REC
L
SW
R
EN
Datasheet 24 Rev. 1.0, 2011-05-27
TLD5045EJ
Application Information
8.3.3 Decentralized Light Module Application - DLM (Input configuration 2)
In this particular input configuration two supply lines are tied together on the DLM. The following input states must
be considered to distinguish between Light Function 1 (DRL mode) and Light Function 2 (PL mode).
1) Condition: DRL = ON, PL = OFF. Desired function: DRL mode (e.g. 400mA LED load current)
2) Condition: DRL = OFF, PL = ON. Desired function: PL mode (e.g. 50mA LED load current)
3) Condition: DRL = ON, PL =ON. Desired function: PL mode (e.g. 50mA LED load current)
To achieve a lower mean LED load current during the PL mode the integrated PWM engine is a useful feature.
The external RPWM and CPWM circuit predefines a dedicated PWM frequency and duty cycle. (for details refer to
Figure 11)
To simulate a module current during light load conditions the ST pin can be connected via resistors to both supply
voltage lines. (refer to Chapter 7 for a detailed description of the ST behavior)
For a decentralized solution without micro controller involvement the possibility to connect a PTC resistor at the
SET pin is a cost effective solution to protect the LED load from thermal destruction.
Figure 16 Application Diagram of Decentralized Light Module without µC (input config 2)
This is a very simplified example of an application circuit. The function must be verified in the real application
SW
GND
FREQ
SET
ST
PWMI
VREC
4
6
7
81
3
5
2
TLD5045
C
FREQ
R
FREQ
R
SET
I
ST,PD
Vbat
Vbat
BCM - module
Wire Harness
Inductance
Light Function 1
(e.g. DRL)
Light Function 2
(e.g. PL)
GND
R
PWM
C
PWM
I
Open_load
I
LED
Decentralized Light Module
EN
C
REC
R
PTC
R
COMP
V
REC
L
SW
R
EN
T
DIM1
T
DIM2
R
DIM 1
TLD5045EJ
Application Information
Datasheet 25 Rev. 1.0, 2011-05-27
8.3.4 Decentralized Light Module Application - DLM (Input configuration 3)
A permanent supply chooses the Light Function 1 (DRL mode) and a second dedicated PWM supply between
100Hz and 200Hz switches to Light Function 2 (PL mode). For this input configuration it is possible to connect the
PWM dimming output of the BCM directly to the PWMI input of the TLD5045. To simulate a module current during
light load conditions the ST pin can be connected via a resistor to the permanent supply voltage line. (refer to
Chapter 7 for a detailed description of the ST behavior)
For a decentralized solution without micro controller involvement the possibility to connect a PTC resistor at the
SET pin is a cost effective solution to protect the LED load from thermal destruction. (for details refer to Figure 15)
Figure 17 Application Diagram of Decentralized Light Module without µC (input config 3)
This is a very simplified example of an application circuit. The function must be verified in the real application
SW
GND
FREQ
SET
ST
PWMI
VREC
4
6
7
81
3
5
2
TLD5045
L
SW
C
FREQ
R
FREQ
R
SET
IST,PD
Vbat
BCM - module
Wire Harness
Inductance
GND
IOpen_load
ILED
Decentralized Light Module
EN
C
REC
R
PTC
Vbat
Light Function 1
(e.g. DRL)
Light Function 2
(e.g. PL)
R
COMP
V
REC
R
EMC
R
EN
R
LIM
D
LIM
Datasheet 26 Rev. 1.0, 2011-05-27
TLD5045EJ
Package Outlines
9 Package Outlines
Figure 18 Outline PG-DSO-8 EP
Green Product (RoHS compliant)
To meet the world-wide customer requirements for environmentally friendly products and to be compliant with
government regulations the device is available as a green product. Green products are RoHS-Compliant (i.e
Pb-free finish on leads and suitable for Pb-free soldering according to IPC/JEDEC J-STD-020).
PG-DSO-8-27-PO V01
14
85
8
14
5
8x
0.41
±0.09 2)
M
0.2 DC A-B
1.27 C
Stand Off
+0
-0.1
0.1
(1.45)
1.7 MAX.
0.08
Seating Plane
C
A
B
4.9
±0.11)
A-BC0.1 2x
3
)
JEDEC reference MS-012 variation BA
1) Does not include plastic or metal protrusion of 0.15 max. per side
2) Dambar protrusion shall be maximum 0.1 mm total in excess of lead width
Bottom View
±0.2
3
±0.2
2.65
0.2
±0.2
D6
M
D 8x
0.64
±0.25
3.9
±0.11)
0.1
0.35 x 45˚
CD2x
+0.06
0.19
8
˚
MAX.
Index Marking
For further package information, please visit our website:
http://www.infineon.com/packages.Dimensions in mm
TLD5045EJ
Revision History
Datasheet 27 Rev. 1.0, 2011-05-27
10 Revision History
Version Date Changes
Rev. 1.0 2011-05-27 Initial Data sheet for TLD5045
Edition 2011-05-27
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2011 Infineon Technologies AG
All Rights Reserved.
Legal Disclaimer
The information given in this document shall in no event be regarded as a guarantee of conditions or
characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any
information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties
and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights
of any third party.
Information
For further information on technology, delivery terms and conditions and prices, please contact the nearest
Infineon Technologies Office (www.infineon.com).
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