TLD5541-1QV Datasheet, PDF (39/82 Pages) Infineon Technologies AG – H-Bridge DC/DC Controller with SPI Interface

H-Bridge DC/DC Controller with SPI Interface
TLD5541-1QV
Analog Dimming
8
Analog Dimming
The analog dimming feature allows further control of the output current. This approach is used to:
• Reduce the default current in a narrow range to adjust to different binning classes of the used LEDs.
• Adjust the load current to enable the usage of one hardware for several LED types where different current
levels are required.
• Reduce the current at high temperatures (protect LEDs from overtemperature).
• Reduce the current at low input voltages (for example, cranking-pulse breakdown of the supply or power
derating).
8.1
Description
The analog dimming feature is adjusting the average load current level via the control of the feedback error
Amplifier voltage (V_FBH-FBL).
The current adjustment is done via a 8BIT SPI parameter (LEDCURRADIM.ADIMVAL). Refer to Figure 21.
V_FBH-FBL
150mV
0
b´11110000
8 BIT SPI adjustment
Figure 21 Analog Dimming Overview
Bitcode
Analog dimming adjustment during Limp Home state:
To enter in Limp Home state the LHI pin must be HIGH.
Note: If the PWMI and the EN/INUVLO are not set to HIGH, it is not possible to enable switching, even during
Limp Home state.
In Limp Home state the analog dimming control is done via the SET pin. A Resistor divider between
IVCC/IVCC_EXT, SET and GND is used to fix a default load current/voltage value (refer to Figure 22 below).
Data Sheet
39
Rev. 1.0, 2016-05-20