LP8861-Q1 Datasheet, PDF (1/43 Pages) Texas Instruments – Low-EMI, High-Performance Four-Channel LED Driver

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LP8861-Q1
SNVSA50A – AUGUST 2015 – REVISED NOVEMBER 2015
LP8861-Q1 Low-EMI, High-Performance Four-Channel LED Driver for Automotive Lighting
1 Features
•1 Qualified for Automotive Applications
• AECQ100 Qualified With the Following Results:
– Device Temperature Grade 1: –40°C to
+125°C Ambient Operating Temperature
• Input Voltage Operating Range 4.5 V to 40 V
• Four High-Precision Current Sinks
– Current Matching 1% (typical)
– LED String Current up to 100 mA/Channel
– Dimming Ratio 10 000:1 at 200 Hz
• Integrated Boost/SEPIC for LED String Power
– Output Voltage up to 45 V
– Switching Frequency 300 kHz to 2.2 MHz
– Boost/SEPIC Synchronization Input
– Spread Spectrum
• Power-Line FET Control for Inrush Current
Protection and Standby Energy Saving
• Extensive Fault Detection and Tolerance Features
– Fault Output
– Input Voltage OVP, UVLO, and OCP
– Open and Shorted LED Fault Detection
– Automatic LED Current Reduction With
External Temperature Sensor
– Thermal Shutdown
• Minimum Number of External Components
3 Description
The LP8861-Q1 is an automotive high-efficiency, low-
EMI, easy-to-use LED driver with integrated
boost/SEPIC converter. It has four high-precision
current sinks that can provide high dimming ratio
brightness control with a PWM input signal.
The boost/SEPIC converter has adaptive output
voltage control based on the LED current sink
headroom voltages. This feature minimizes the power
consumption by adjusting the voltage to lowest
sufficient level in all conditions. Boost/SEPIC
controller supports spread spectrum for switching
frequency and an external synchronization with
dedicated pin. The high switching frequency allows
the LP8861-Q1 to avoid disturbance for AM radio
band.
The LP8861-Q1 has option to drive an external p-
FET to disconnect the input supply from the system in
the event of a fault and reduce inrush current and
standby power consumption. The device has ability to
reduce LED current based on temperature measured
with external NTC sensor to protect LED from
overheating and extend LED life time.
The input voltage range for the LP8861-Q1 is from
4.5 V to 40 V to support automotive stop/start and
load dump condition. The device supports PWM
brightness dimming ratio 10 000:1 for input PWM
frequency
200 Hz. The LP8861-Q1 integrates extensive fault
detection and protection features.
2 Applications
Automotive Infotainment, Instrument Clusters, and
Backlighting Systems
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LP8861-Q1
TSSOP (20)
6.50 × 4.50 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
VIN
4.5...40 V
RISENSE
Simplified Schematic
Q1
L1
D1
Up to 45 V
RGS
CIN
CLDO
VLDO
RFSET
BRIGHTNESS
EN
CIN BOOST
SD
VSENSE_N
VIN
SW
FB
LDO
LP8861-Q1 OUT1
OUT2
FSET
OUT3
SYNC
OUT4
PWM
VDDIO/EN
FAULT
TSET
TSENSE
ISET
PGND GND PAD
COUT
R2
R1
CFB
Up to 100 mA/string
R7
R6
RISET
VLDO
R4
R3
RTº
R5
NTC
100
95
90
85
80
75
70
65
60
0
System Efficiency
VIN=5V
VIN=8V
VIN=12V
VIN=16V
20
40
60
80
100
Brightness (%)
C010
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.