LP3958TL/NOPB National Semiconductor, LP3958TL/NOPB Datasheet - Page 24

• Manufacturer Part Number: LP3958TL/NOPB
• Description: IC LED DRVR WT/CLR BCKLT 25-USMD
• Manufacturer: National Semiconductor
• Series: PowerWise®r
• Type: Backlight, White LED, Color LEDr

Specifications of LP3958TL/NOPB

• Constant Current: Yes
• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 5
• Internal Driver: Yes
• Type - Primary: Backlight, Light Management Unit (LMU)
• Type - Secondary: White LED
• Frequency: 1MHz
• Voltage - Supply: 3 V ~ 5.5 V
• Voltage - Output: 18V
• Mounting Type: Surface Mount
• Package / Case: 25-MicroSMD
• Operating Temperature: -30°C ~ 85°C
• Internal Switch(s): Yes
• Efficiency: 90%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output / Channel: -
• Other names: LP3958TLTR

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LP3958 Register Bit Explanations
Each register is shown with a key indicating the accessibility of the each individual bit, and the initial condition:
CONTROL REGISTER (00H) – KEYPAD LEDS CONTROL REGISTER
KEYPAD (01H) – KEYPAD BALANCE AND BRIGHTNESS CONTROL REGISTER
KEYP_PWM
R - 0
D7
RW - 0
D7
RW - 0
KEYP_PWM
EN_KEYP
CC_SW
K1SW
K2SW
K3SW
BALANCE[2:0]
BRIGHT[2:0]
OVL
D6
EN_KEYP
RW - 0
D6
BALANCE[2:0]
RW - 0
Register Bit Accessibility and Initial Condition
Key
RW
R
–0,–1
D5
Bits 6-4
Bits 3-1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 3
Bit 2
Bit 1
CC_SW
RW - 1
D5
RW - 0
PWM balance for KEYPAD outputs
PWM brightness control for KEYPAD outputs
0 – Overlapping mode disabled
1 – Overlapping mode enabled
0 - Internal KEYPAD PWM control disabled
1 - Internal KEYPAD PWM control enabled
0 – KEYPAD outputs disabled
1 – KEYPAD outputs enabled
0 – Constant current sink mode
1 – Switch mode
0 – KEYPAD1 disabled
1 – KEYPAD1 enabled
0 – KEYPAD2 disabled
1 – KEYPAD2 enabled
0 – KEYPAD3 disabled
1 – KEYPAD3 enabled
Bit Accessibility
Read/write
Read only
Condition after POR
D4
R - 0
D4
24
RW - 0
D3
RW - 0
K1SW
D3
BRIGHT[2:0]
RW - 0
D2
RW - 0
K2SW
D2
RW - 0
D1
RW - 0
K3SW
D1
RW - 0
OVL
D0
R - 0
D0