LP3942 Datasheet, PDF (13/20 Pages) National Semiconductor (TI) – The Dual RGB LED Controller with 1.5x/2x Charge Pump and SPI Interface

Application Information
The following examples describe 4 different ways to use LP3942 to drive different LEDs (2 RGBs, 4 RGBs, 6 Blue LEDs)
Example 1: Normal Use – 2 RGBs
• Charge pump in 1.5x mode, V_OUT = 4.5V
• Non overlapping constant current mode in use
• RGB1 and RGB2 have different control
• Imax(R1, R2) limited to 10 mA by RR
• Imax(G1, G2) limited to 15 mA by RG
• Imax(B1, B2) limited to 20 mA by RB
• Framing → I_LOAD(max) = 40 mA → low noise to input.
• See Electrical Characteristics for output voltage and current specifications in different conditions
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