LX1745CPW Microsemi Analog Mixed Signal Group, LX1745CPW Datasheet - Page 3

• Manufacturer Part Number: LX1745CPW
• Description: IC LED DRVR WT/CLR BCKLT 20TSSOP
• Manufacturer: Microsemi Analog Mixed Signal Group
• Type: Backlight, White LED, Color LEDr

Specifications of LX1745CPW

• Constant Current: Yes
• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 3
• Internal Driver: Both
• Type - Primary: Backlight
• Type - Secondary: Color, White LED
• Voltage - Supply: 1.6 V ~ 6 V
• Voltage - Output: 25V
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 100mA
• Internal Switch(s): Yes
• Efficiency: 90%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency: -

Copyright © 2000
Rev. 1.2, 2006-02-27
SHDNx
LSHDN
Name
ADJx
GND
DRV
SRC
OVP
SWx
BRT
REF
LFB
FBx
CS
IN
TM
Unregulated IC Supply Voltage Input – Input range from +1.6V to 6.0V. Bypass with a 1μF or greater capacitor
for operation below 2.0V.
LED MOSFET Gate Driver – Connects to an external N-Channel MOSFET.
LED MOSFET Current Sense Input - Connects to the External N-Channel MOSFET Source.
Over Voltage Programming Pin – Connects to a resistor divider between the output load and GND to set the
maximum output voltage. OVP has a voltage threshold of 1.2V
LED Current Feedback Input – Connects to a current sense resistor between the LED output load and GND to
set the LED drive current.
Common terminal for ground reference.
LED Dimming Signal Input – Provides the internal reference, via an internal filter and gain resistor, allowing for a
dynamic output LED current adjustment that corresponds to the PWM input signal duty cycle. Either a PWM
signal or analog voltage can be used. The actual BRT pin voltage range is from V
current sense resistor power dissipation by selecting a range for V
Buffered Reference Output – Connected to the internal bandgap reference voltage of 1.2V.
LCD Bias Inductor Switch Connection – Internally connected to the drain of a 28V N-channel MOSFET. SW is
high impedance in shutdown.
Feedback Input – Connect to a resistive divider network between the output and GND to set the output voltage
between V
LCD Bias Adjustment PWM Signal Input – Connect to an RC filter allowing for dynamic output voltage
adjustment >±15%, corresponding to a varying duty cycle. Either a PWM signal or analog voltage can be used.
The ADJ input voltage range is from 0.9V to V
internal reference is used.
LED Driver Active-Low Shutdown Input – A logic low shuts down the LED driver circuitry and reduces the supply
current by 60μA (Typ). Pull LSHDN high for normal operation.
LCD Bias Active-Low Shutdown Input – A logic low shuts down the LCD Bias circuitry and reduces the supply
current by 60μA (Typ). Pull SHDNx high for normal operation.
Current-Sense Amplifier Input – Connecting a resistor between CS and GND sets the peak inductor current
limit.
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
CC
(IN) and 25V. The feedback threshold is 1.29V.
F U N C T I O N A L P I N D E S C R I P T I O N
Integrated Products Division
®
Microsemi
IN
Triple Output Boost – LED Driver / LCD Bias
DC. The ADJx pin should be connected to ground when the
Description
P
RODUCTION
BRT
= 0.0V to 0.5V.
D
ATASHEET
IN
to GND. Minimize the
LX1745
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