The CAT32 is a DC/DC step up converter that delivers a regulated output current. Operation at a constant switching frequency of 1.2MHz allows the device to be used with very small value external inductor and ceramic capacitors.
The CAT32 is targeted to drive multiple white light-emitting diodes (LEDs) connected in series and provides the necessary regulated current to control the brightness and the color purity. An external resistor R
controls the output current level. LED currents of up to 40mA can be supported over a wide range of input supply voltages from 2V to 7V, making the device ideal for battery-powered applications.
A high voltage output stage allows up to 4 White LEDs to be driven in series. Series drive provides inherent current matching.
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 'near zero' quiescent current.
In addition to overcurrent limiting protection, the device also includes detection circuitry to ensure protection against open-circuit load fault conditions.
The device is available in a low profile (1mm max height) 6-lead TSOT-23 package.

• Low quiescent ground current (0.5 mA typical)
• Power efficiency over 80%
• Compatible pinout with LT1932
• Adjustable output current (up to 40 mA)
• High frequency 1.2 MHz operation
• Input voltage operation down to 2.0 V
• Low resistance (0.5Ω) high voltage power switch
• Drives up to 4 White LEDs in series
• Shutdown current less than 1µA
• Load fault protection against open-circuits
• Low value external components