Sipex introduces four-channel charge pump LED driver

March 22, 2005
Date Announced: 22 Mar 2005 Sipex Corporation has further enhanced its family of LED drivers with the SP6687. This high efficiency charge pump independently controls up to four white LEDs and is ideal for backlighting color displays in portable applications such as cell phones, digital cameras, portable MP3 players and PDAs.The SP6687 can generate regulated output current using 3 distinct operating modes. At high input voltages, it functions as a linear regulator. At low input voltages, it functions as a 1.5X charge pump, boosting input voltage to maintain desired LED forward current. And a third mode allows it to operate as a 2X charge pump. This tri-mode architecture in addition to low 1uA shutdown current enables greater efficiency, constant brightness and longer battery life.The SP6687 provides a matched current source of up to 120mA total (30mA per LED) for all channels. The LED current is user programmable by using a single external current set resistor, which sets the current for all LEDs at approximately 440 times the current through the set resistor. Brightness can be adjusted either by varying the value of the set resistor or by employing a PWM dimming scheme. Since the part is designed with integrated current sense circuitry, there is no external current sensing resistor required. The part operates at 1MHz frequency.SP6687 Key Features (Typical)* Independent PWM dimming of up to 4 LEDS* High efficiency operation >90%, Peak efficiency of 95%* Tri-mode charge pump maintains efficiency across battery life* Two dimming control methods: PWM and DC voltage* Low 1uA shutdown current* Built in soft-start* Thermal shutdown protection* Short circuit and output over-voltage protection* Optimized for Lithium Ion batteries* Pin compatible to SC604Pricing and AvailabilityThe SP6687 samples are available now. The part is rated over the industrial temperature range of -40 degrees C to +85 degrees C and is housed in a 4mm x 4mm QFN package. Pricing for the SP6687 begins at $1.09 in 1000 piece quantities.

Sharon Guerrand Phone: 408-934-7500 Fax: 408-935-7600


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