TPS61187 Datasheet, PDF (1/25 Pages) Texas Instruments – WLED Driver for Notebooks with PWM Interface and Auto Phase Shift

TPS61187
www.ti.com
SLVSA85D – JUNE 2010 – REVISED FEBRUARY 2012
WLED Driver for Notebooks with PWM Interface and Auto Phase Shift
Check for Samples: TPS61187
FEATURES
1
• 4.5 V to 24 V Input Voltage
• 38 V Maximum Output Voltage
• Integrated 2 A 40 V MOSFET
• 300 kHz to 1 MHz Programmable Switching
Frequency
• Adaptive Boost Output to WLED Voltages
• Wide PWM Dimming Frequency Range
– 100 Hz to 50 KHz for Direct PWM Mode
– 100 Hz to 22 KHz for Frequency
Programmable Mode
• 100:1 Dimming Ratio at 20 kHz
• 10000:1 Dimming Ratio at 200 Hz (Direct PWM
mode)
• Small External Components
• Integrated Loop Compensation
• Six Current Sinks of 30 mA Max
• 1.5% (Typ) Current Matching
• PWM Brightness Interface Control
• PWM Phase Shift Mode Brightness Dimming
Method or Direct PWM Dimming Method
• 4 kV HBM ESD Protection
• Programmable Over Voltage Threshold
• Built-in WLED Open/Short Protection
• Thermal Shutdown
• 20 Lead 4mm × 4mm × 0.8 mm TQFN Package
APPLICATIONS
• Notebook LCD Display Backlight
DESCRIPTION
The TPS61187 IC provides a highly integrated WLED
driver solution for notebook LCD backlight. This
device has a built-in high efficiency boost regulator
with integrated 2.0A /40V power MOSFET. The six
current sink regulators provide high precision current
regulation and matching. In total, the device can
support up to 60 WLEDs. In addition, the boost output
automatically adjusts its voltage to the WLED forward
voltage to optimize efficiency.
The TPS61187 supports the auto phase shift
dimming method and direct PWM dimming method.
During phase shift PWM dimming, the WLED current
is turned on/off at the duty cycle controlled by the
input PWM signal and each channel is shifted
according to the frequency determined by an
integrated pulse width modulation (PWM) signal. The
frequency of this signal is resistor programmable,
while the duty cycle is controlled directly from an
external PWM signal input to the PWM pin. During
direct PWM dimming, the WLED current is turned
on/off synchronized with the input PWM signal.
4.5V~24V
L1
10uH
D1
C1
2.2uF
C3
4.7uF
R4
Open
R5
VIN FAULT
SW
C2
1.0 uF
R7
1.2 KW
VDDIO
EN
PGND
OVC
R8
10 KW
FSLCT
R3
499 KW
PWM
VDD_GPIO
R1
62 KW
ISET
TPS61187
IFB1
IFB2
IFB3
IFB4
IFB5
IFB6
Open
FPO
AGND
RFPWM
/MODE
19.8 mA
R2
9.09 KW
Figure 1. Typical Application – Phase Shift PWM
Mode
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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