EMD2794

Preliminary EMD2794/EMD2795 Elite MicroPower Inc. Regulated Switched Capacitor LED Current Source with Analog and PWM Brightness Control General Description The EMD2794/EMD2795 is a 1.5x/1.0x charge pump that provides four regulated current sources. It accepts an input voltage range from 2.7V to 5.5V and maintains a constant current determined by an external resistor. The EMD2794/EMD2795 delivers up to 80mA of load current to accommodate four White LEDs. The switching „ „ „ „ „ „ „ „ „ „ Features „ Regulated current sources with ±0.5% matching High efficiency 3/2 boost function Drives one to four white LEDs. 2.7V to 5.5V input range Up to 80mA output current Analog brightness control frequency is fixed at 1.2MHz to make noise filtering easier. Brightness control can be done by both linear and PWM techniques. Linear control is achieved by applying 0V to 3.0V to the BRGT pin to linearly vary the LED current. PWM Active-low or high shutdown input (‘94/95) Very small solution size and no inductor Shutdown Current < 1μA 1.2MHz switching frequency Constant frequency generates predictable noise spectrum technique is to apply a clock to the EN pin to having brightness varying with clock duty. Shutdown is done by applying low (high for 2795) to the pin EN. The VIN current drops to less than 1.0uA in shutdown mode. The EMD2794/EMD2795 is available in a TQFN-16 & FBP-16 3x3 package. Mi Elite MicroPower Inc. reserves the right to make changes to improve reliability or manufac...