LP3958TL/NOPB National Semiconductor, LP3958TL/NOPB Datasheet - Page 24
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LP3958TL/NOPB
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
Datasheet
1.LP3958TLNOPB.pdf
(28 pages)
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
www.national.com
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