austriamicrosystems AG AS3691
The AS3691 features four high precision current sources for driving up to four LED strings (RGB or single color leds). Each of the four currents sources can be controlled independently by PWM inputs. The full scale current value is set by external resistors.GENERAL DESCRIPTION
Very wide output voltage current source voltage compliance − Down to 0.41V 2) − Up to 15V Integrated overtemperature protection Separate sense pads (Rfb1-Rfb4) for easy and precise PCB Layout Package − DIE − QFN24 4x4mm 15V is sufficient for most applications as the AS3691 dose not switch off the LED current completely 2) 2 KeyFEATURES
4 x 400mA constant current outputs Programmable with external resistors 4 independent PWM inputs Absolute current accuracy +/-0.5% ’ Automatic Supply Regulation’ to reduce power 1) dissipation 1) 3APPLICATIONS
General Lighting Backlighting RGB Backlighting for LCD TV/Monitors with White Color Balancing Patent Pending 4 Application Diagrams Figure 1 – Application Diagram of AS3691 for Single Color Lighting (Single Module shown) VDD Csup 100nF Rvdd Cvdd 100nF UV VREG 15 UV1 22 CURR1 1 Vc UV2 20 CURR2 17 Vc UV3 10 CURR3 13 Vc UV4 8 Vc CURR4 5 UV VDD AS3691 D1 Ref T1 I1 R1 23 ON1 2 24 RFB1 19 RES1 ON2 R2 16 18 RFB2 T2 I2 R3 11 RES2 ON3...