LP3958 Datasheet, PDF (3/28 Pages) National Semiconductor (TI) – Lighting Management Unit with High Voltage Boost Converter

Connection Diagrams and Package Mark Information (Continued)
PIN DESCRIPTIONS
Pin #
5E
5D
5C
5B
5A
4E
4D
4C
4B
4A
3E
3D
3C
3B
3A
2E
2D
2C
2B
2A
1E
1D
1C
1B
1A
Name
SW
FB
KEY1
KEY2
KEY3
GND_SW
NRST
SCL
IKEY
GND_KEY
VDD2
VDDIO
SDA
GPIO[2]
GPIO[0] / PWM
GND_WLED
GNDT
VDD1
VREF
GPIO[1]
MAIN
SUB
VDDA
GND
IRT
Type
Output
Input
Output
Output
Output
Ground
Input
Logic Input
Input
Ground
Power
Power
Logic Input/Output
Logic Input/Output
Logic Input/Output
Ground
Ground
Power
Output
Logic Input/Output
Output
Output
Output
Ground
Input
Description
Boost Converter Power Switch
Boost Converter Feedback
Keypad LED Output 1 (Current Sink)
Keypad LED Output 2 (Current Sink)
Keypad LED Output 3 (Current Sink)
Power Switch Ground
External Reset, Active Low
Clock Input for I²C Compatible Interface
External Keypad LED Maximum Current Set Resistor
Ground for KEY LED Currents
Supply Voltage 3.0...5.5 V
Supply Voltage for Digital Input/Output Buffers and Drivers
Data Input/Output for I²C Compatible Interface
General Purpose Logic Input/Output
General Purpose Logic Input/Output / External PWM Input
Ground for White LED Currents (MAIN and SUB Outputs)
Ground
Supply Voltage 3.0...5.5 V
Reference Voltage (1.23V)
General Purpose Logic Input/Output
MAIN Display White LED Current Output (Current Sink)
SUB Display White LED Current Output (Current Sink)
Internal LDO Output (2.80V)
Ground for Core Circuitry
Oscillator Frequency Set Resistor
3
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