EVAL BOARD MCP1664 LED DRIVER
The MCP1664 is a compact, space-efficient, fixed-frequency, non-synchronous step-up converter optimized to drive multiple strings of LEDs with constant current powered from two and three-cell alkaline or NiMH/NiCd as well as from one-cell Li-Ion or Li-Polymer batteries. The device integrates a 36V, 400 m low-side switch, which is protected by the 1.8A cycle-by-cycle inductor peak current limit operation. The MCP1664 starts up without high inrush current or output overshoot. All compensation and protection circuitry is integrated to minimize the number of external components. The internal feedback (VFB) voltage is set to 300 mV for low power dissipation when sensing and regulating the LED current. A single resistor sets the LED current. The device features an UVLO which avoids start-up with low inputs or discharged batteries for two cell-powered applications. The MCP1664 features an open load protection (OLP) which turns off the operation in situations when the LED string is accidentally disconnected or the feedback pin is short-circuited to GND. While in Shutdown mode (EN = GND), the device stops switching, and consumes 40 nA typical of input current.