TLD5045EJ_15 Datasheet, PDF (24/30 Pages) Infineon Technologies AG – 700mA High Integration - DC/DC Step-Down Converter

Infineon® LITIX™ Power
TLD5045EJ
Application Information
8.3
TLD5045EJ in different LED Applications
8.3.1 TLD5045EJ in a Body Control Module (BCM) with µC Interface
Figure 8-5 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 R_SET is used to set the required peak current for the LED load (refer to Figure 8-1
for more details).
To set the desired switching frequency of the buck regulator the external R_FREQ and C_FREQ network must be
connected to GND (reference values are given in Figure 8-3).
Vs = 5V to 40V
ILED
C_REC
VREC
1
L_SW
SW
8
open load status
connected to µC
V_DD
R_ST
ST
2
connect to µC pin
R_SET
3 EN
4 SET
7
GND
FREQ 6
R_{FREQ CFREQ}
R_COMP
TLD5045
V_REC
PWMI 5
R_EMC
PWM dimming via µC
Figure 8-5 Simplified Application Diagram TLD5045EJ
Note: This is a very simplified example of an application circuit. The function must be verified in the real
application
Data Sheet
24
Revision 1.0
2015-05-28