 English |
|
|
|
|
|
|
|
| LM3463_12 Datasheet, PDF (23/40 Pages) Texas Instruments – LM3463 Dynamic Headroom Controller with Thermal Control Interface and Individual Channel Dimming Control | |||
| |||
| ◁ |
www.ti.com
Primary power supply
To control circuit of
R1
primary power supply
VRAIL
VFB
LM3463
RDHC
VIN
OutP
VLedFB
2.5V
R2
GND
GND REFRTN
RFB1
RFB2
Figure 10. Connecting the LM3463 to a power supply
LM3463
SNVS807 â MAY 2012
PROCEDURES
Begin power
supply selection
Determine:
ILEDx, VRAIL(peak) and VRAIL(nom)
Calculate the required maximum output
Power, PRAIL(peak) of the power supply
Prepare a power converter which has a
maximum output power > POUT(nom) and a
maximum output voltage > VRAIL(peak)
REMARKS
VRAIL(peak) is the highest output voltage
that the power converter needs to
deliver.
ILEDx is the forward current of an LED
string.
PRAIL(peak)
=
No. of
output ch.
ILEDx
VRAIL(peak)
The power converter must be able to
deliver a power no less than PRAIL(peak)
even if the VRAIL is pushed to the
maximum by the LM3463, VRAIL(peak)
Adjust R1 and R2 to reduce the nominal
output voltage of the power converter to
VRAIL(nom)
Adjust the value of R1 and R2 so as to
meet the equation:
VRAIL(nom) = VFB
R2
R1 + R2
End of power
supply selection
Figure 11. Procedures of selecting the primary power supply
Choosing the proper Primary Power Supply
If the primary power supply is an off-the-shelf power converter, it is essential to make certain that the power
converter is able to withstand the VRAIL(peak). In order to allow DHC, the nominal output voltage of the primary
power supply needs to be adjusted to below VLED-MIN-HOT as well. The suggested procedures for selecting the
proper power supply are as shown in Figure 11.
Copyright © 2012, Texas Instruments Incorporated
Product Folder Links: LM3463
Submit Documentation Feedback
23
|
▷ |
German
Russian
Spanish
Italian
Polish
Chinese
Japanese
Korean
French
Portuguese