LP3943ISQ National Semiconductor, LP3943ISQ Datasheet - Page 10

• Manufacturer Part Number: LP3943ISQ
• Description: LED Driver IC
• Manufacturer: National Semiconductor

Specifications of LP3943ISQ

• Driver Case Style: LLP
• Peak Reflow Compatible (260 C): No
• Leaded Process Compatible: No
• No. Of Pins: 24
• Package / Case: 24-LLP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Application Notes
PWM1 register determines the duty cycle of DIM1. The LED outputs are LOW (LED on) when the count is less than the value in PWM1 and HIGH (LED off) when
it is greater. If PWM1 is programmed with 0x00, LED output is always HIGH (LED off).
The duty cycle of DIM1 is: PWM1/256
Default value is 50% duty cycle.
BINARY FORMAT FOR SELECTOR REGISTERS — ADDRESS 0x06 to 0x09
Bit #
Default value
Bit #
Default value
Bit #
Default value
Bit #
Default value
Bit #
Default value
B1
0
0
1
1
B1
B1
B1
B1
7
0
7
0
7
0
7
0
7
1
(Continued)
LED15
LED11
LED3
LED7
LED States With Respect To Values in "B1" and "B0"
B0
B0
B0
B0
6
0
6
0
6
0
6
0
6
0
Address 0x05 (PWM1)
Address 0x06 (LS0)
Address 0x07 (LS1)
Address 0x08 (LS2)
Address 0x09 (LS3)
B1
B1
B1
B1
5
0
5
0
5
0
5
0
5
0
B0
0
1
0
1
LED10
LED14
LED2
LED6
10
B0
B0
B0
B0
4
0
4
0
4
0
4
0
4
0
B1
B1
B1
B1
3
0
3
0
3
0
3
0
3
0
LED13
LED1
LED5
LED9
B0
B0
B0
B0
2
0
2
0
2
0
2
0
2
0
Output Hi-Z
(LED off)
Output LOW
(LED on)
Output dims
(DIM0 rate)
Output dims
(DIM1 rate)
Function
B1
B1
B1
B1
1
0
1
0
1
0
1
0
1
0
LED12
LED0
LED4
LED8
B0
B0
B0
B0
0
0
0
0
0
0
0
0
0
0