TPS61185
www.ti.com
SLVSAA1A –APRIL 2010–REVISED MAY 2010
WLED Driver for Notebooks with PWM Control Interface
Check for Samples: TPS61185
The TPS61185 supports the PWM method for
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FEATURES
brightness dimming. Simply tie the unused current
sinks to ground if fewer than eight are needed. During
PWM dimming, each of the eight current regulators is
turned on/off at the duty cycle determined by an
external pulse width modulation (PWM) signal input to
the PWM pin. The frequency at which each current
regulator turns on/off follows the input PWM signal on
the PWMIN pin if the MODE pin is grounded. If the
MODE pin is left floating or tied high, the regulators
turn on/off at the frequency programmed by an
external resistor on the FPWMO pin.
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4.2 V to 24 V Input Voltage
Integrated 2 A/40 V MOSFET
600 kHz to 2 MHz Programmable Switching
Frequency
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Adaptive Boost Output for Best Efficiency
Design to Use Small L-C Components
Integrated Loop Compensation
Eight 25 mA Current Sinks
Up to 10 WLED in Series
The TPS61185 IC supports boost switch frequency
programming from 600kHz to 2MHz by an external
resistor on the FSW pin. The device also provides a
driver output for an optional external PFET connected
between the input and inductor for truly disconnecting
the battery from LED during the shutdown or fault
1% Current Matching and Accuracy
PWM Brightness Interface Control
200 mV Ripple Under PWM Dimming
Driver for Input/Output Isolation PFET
Programmable Over Voltage Threshold
protection.
The
device
integrates
resistor
100 Hz to 5 kHz Programmable PWM Dimming
Frequency
programmable over-voltage protection, soft-start, and
thermal shutdown.
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Up to 20 kHz Direct PWM Dimming Frequency
The TPS61185 IC has a built-in linear regulator to
power the internal circuits of the IC. The device is in a
4 mm × 4 mm QFN package.
Enhanced Electrostatic Discharge Immunity
Level
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Built-in WLED Open/Short Protection
Over Temperature Protection
Typical Application Circuit
L1
D1
10 mH
4.2V~24V
24 Pin 4 mm × 4 mm QFN Package
C2
4.7 mF
R3
1 MW
C1
4.7 mF
APPLICATIONS
R4
54.9 KW
FAULT
VIN
SW1 SW2
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Notebook LCD Display Backlight
PGND1
PGND2
C4
1 mF
VDD
C3
1 mF
OVP
DESCRIPTION
TPS61185
FPWMO
EN
The TPS61185 IC provides highly integrated
solutions for large-size LCD backlighting. This device
has a built-in high efficiency boost regulator with
integrated 2 A/40 V power MOSFET. The eight
current sink regulators provide high precision current
regulation and matching. In total, the device can
support up to 80 LEDs. In addition, the boost output
automatically adjusts its voltage to the WLED forward
voltage to improve efficiency.
R5
715 KW
PWMIN
Open Freq Pro
Direct
MODE
ISET
GND
IFB1
IFB2
IFB3
IFB4
IFB5
IFB6
IFB7
IFB8
R1
62 KW
FSW
AGND
R2
604 KW
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Copyright © 2010, 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.