The CAT4237TD-GT3 is a high voltage CMOS boost white LED Driver for use with handheld devices. The DC/DC step-up converter delivers an accurate constant current ideal for driving LEDs. Operation at a constant switching frequency of 1MHz allows the device to be used with small value external ceramic capacitors and inductor. LEDs connected in series are driven with a regulated current set by the external resistor R1. LED currents up to 40mA can be supported over a wide range of input supply voltages from 2.8 to 5.5V, making the device ideal for battery-powered applications. The high-voltage output stage is perfect for driving six, seven or eight white LEDs in series with inherent current matching in LCD backlight applications. LED dimming can be done by using a DC voltage, a logic signal or a pulse width modulation (PWM) signal. The shutdown input pin allows the device to be placed in power-down mode with zero quiescent current.
