Texas Instruments LM3431 Evaluation Board LM3431EVAL/NOPB LM3431EVAL/NOPB Scheda Tecnica
Codici prodotto
LM3431EVAL/NOPB
LM3431
VIN
EN
FF
SGND
THM
VCC
REF
REFIN
SNS1
NDRV3
SNS3
NDRV1
NDRV2
SNS2
LG
CS
PGND
COMP
MODE/F
RT
CFB
AFB
SC
SS/SH
DLY
DIM
ILIM
+
Ch.2/
Ch.3
Ch.2
Ch.3
PWM Dim
input
Vin: 5V to 36V
VCC
LEDOFF
SNVS547G – NOVEMBER 2007 – REVISED MAY 2013
3-Channel Constant Current LED Driver with Integrated Boost Controller
Check for Samples:
1
FEATURES
DESCRIPTION
The LM3431 is a 3-channel linear current controller
2
•
LM3431Q/LM3431AQ are Automotive Grade
combined with a boost switching controller ideal for
Products that are AEC-Q100 Grade 1 Qualified
driving
LED
backlight
panels
in
space
critical
(–40°C to 125°C operating junction
applications. The LM3431 drives 3 external NPN
temperature)
transistors or MOSFETs to deliver high accuracy
•
3-Channel Programmable LED Current
constant current to 3 LED strings. Output current is
adjustable to drive strings in excess of 200 mA. The
adjustable to drive strings in excess of 200 mA. The
•
High Accuracy Linear Current Regulation
LM3431 can be expanded to drive as many as 6 LED
•
Analog and Digital PWM Dimming Control
strings.
•
Up to 25kHz Dimming Frequency
The boost controller drives an external NFET switch
•
>100:1 Contrast Ratio
for step-up regulation from input voltages between 5V
•
Integrated Boost Controller
and
36V.
The
LM3431
features
LED
cathode
feedback
to
minimize
regulator
headroom
and
•
5V-36V Input Voltage Range
optimize efficiency.
•
Adjustable Switching Frequency up to 1MHz
A DIM input pin controls LED brightness from analog
•
LED Short and Open Protection
or digital control signals. Dimming frequencies up to
•
Selectable Fault Shutdown or Automatic
25 kHz are possible with a contrast ratio of 100:1.
Restart
Contrast ratios greater than 1000:1 are possible at
•
Programmable Fault Delay
lower dimming frequencies.
•
Programmable Cycle by Cycle Current Limit
The LM3431 eliminates audible noise problems by
•
Output Over Voltage Protection
maintaining constant output voltage regulation during
LED dimming. Additional features include LED short
LED dimming. Additional features include LED short
•
No Audible Noise
and open protection, fault delay/error flag, cycle by
•
Enable Pin
cycle current limit, and thermal shutdown for both the
•
LED Over-Temperature Shutdown Input
IC and LED array. The enhanced LM3431A features
reduced offset voltage for higher accuracy LED
reduced offset voltage for higher accuracy LED
•
Thermal Shutdown
current.
•
TSSOP-28 Exposed Pad Package
APPLICATIONS
•
Automotive Infotainment Displays
•
Small to Medium Format Displays
TYPICAL APPLICATION CIRCUIT
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Copyright © 2007–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.