CAT4238TD-GT3

The CAT4238TD-GT3 is a DC/DC Step-up Converter delivers an accurate constant current ideal for driving LEDs. Operation at a fixed 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 up to 5.5V, making the device ideal for battery-powered applications. The CAT4238 high-voltage output stage is perfect for driving mid-size and large panel displays containing up to ten white LEDs in series. 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.

• Drives high voltage LED strings (38V)
• Up to 87% efficiency
• Low quiescent ground current of 0.6mA
• Adjustable output current
• 1MHz Fixed frequency low noise operation
• Soft start in-rush current limiting
• Shutdown current less than 1μA
• Open LED overvoltage protection
• Automatic shutdown at 1.9V (UVLO)
• Thermal overload protection

Applications

Sensing & Instrumentation, Consumer Electronics, Portable Devices