LP3958 Datasheet, PDF (1/36 Pages) National Semiconductor (TI) – Lighting Management Unit with High Voltage Boost Converter

LP3958
www.ti.com
SNVS423C – JANUARY 2006 – REVISED MARCH 2013
Lighting Management Unit with High Voltage Boost Converter
Check for Samples: LP3958
FEATURES
1
•2 High-Efficiency Boost Converter With
Programmable Output Voltage
• Two Individual Drivers for Serial Display
Backlight LEDs
• Three Drivers for Serial Keypad LEDs
• Automatic Dimming Controller
• Stand Alone Serial Leypad LEDs Controller
• Three General-Purpose IO Pins
• 25-Bump DSBGA Package: 2.54mm x 2.54mm
x 0.6mm
APPLICATIONS
• Cellular Phones and PDAs
• MP3 Players
• Digital Cameras
DESCRIPTION
LP3958 is a Lighting Management Unit for portable
applications. It is used to drive display backlight and
keypad LEDs. The device can drive 5 separately
connected strings of LEDs with high voltage boost
converter.
The keypad LED driver allows driving LEDs from high
voltage boost converter or separate supply
voltage.The MAIN and SUB outputs are high
resolution current mode drivers. Keypad LED outputs
can be used in switch mode and current mode.
External PWM control can be used for any selected
outputs.
The device is controlled through 2-wire low voltage
I²C compatible interface that reduces the number of
required connections.
LP3958 is offered in a tiny 25-bump DSBGA
package.
Typical Application
Li-Ion Battery
or Charger
C_IN C_VDD
10 PF 100 nF
C_VDDA
C_VREF
R_KEY
R_RT
1 PF
100 nF
V_DDIO
L1
10 PH
VDD1
VDD2
VDDA
VREF
IKEY
IRT
MCU
R_SDA
C_VDDIO
100 nF
SDA
SCL
NRST
VDDIO
D1
SW
FB
MAIN
LP3958
SUB
KEY1
KEY2
KEY3
GND 1-5
GPIO[2]
GPIO[1]
GPIO[0]/PWM
I_MAX = 70 mA
V_OUT = 8...18 V
C_OUT
2 x 4.7 éF
MAIN
BACKLIGHT
0...25 mA/LED
SUB
BACKLIGHT
0...25 mA/LED
3 STRINGS
OF 4 LEDS
FOR
KEYPAD
1
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2
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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