TLD5045EJ_15 Datasheet, PDF (26/30 Pages) Infineon Technologies AG – 700mA High Integration - DC/DC Step-Down Converter

Infineon® LITIX™ Power
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. 1) Condition: DRL = ON, PL = OFF. Desired function: DRL mode (e.g. 400mA LED load current)
2. 2) Condition: DRL = OFF, PL = ON. Desired function: PL mode (e.g. 50mA LED load current)
3. 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 8-2)
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.
Vbat
Vbat
Wire Harness
Inductance
Decentralized Light Module
Light Function 1
(e.g. DRL)
BCM - module
Light Function 2
(e.g. PL)
GND
T_DIM2
IOpen_load
VREC
1
R_EN ^CREC
3 _EN
TDIM1
RDIM1
CPWM
5 PWMI
RPWM
I_ST,PD
2
ST
ILED
LSW
SW
8
7
GND
FREQ 6
RFREQ _CFREQ
R_COMP
SET 4
V_REC
R_SET
TLD5045 ^RPTC
Figure 8-7 Application Diagram of Decentralized Light Module without µC (input config 2)
Note: This is a very simplified example of an application circuit. The function must be verified in the real
application
Data Sheet
26
Revision 1.0
2015-05-28