LED Driver IC; Device Type:LED; Display Interface:7-segment numeric LED digits, bar graph, or discrete LEDs; Supply Voltage Max:5.5V; Termination Type:SMD; Package/Case:5-TSOT-23; No. of Pins:5 ;RoHS Compliant: Yes
Topology = Step-Up / Outputs = 1 / Switching Frequency MHz = 1 / Input Voltage Min. V = 2 / Input Voltage Max. V = 5.5 / Output Current mA = 40 / Output Voltage V = 38 / Operating Temperature Min. °C = -40 / Operating Temperature Max. °C = 150 / Package Type = TSOT-23 / Pins = 5 / Mounting Type = SMD / MSL = Level-1 / Packaging = Tape & Reel / Length mm = 2.9 / Width mm = 1.6 / Height mm = 0.9 / Reflow Temperature Max. °C = 260
The CAT4238 is a DC/DC step-up converter that 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. In addition to thermal protection and overload current limiting the device also enters a very low power operating mode during Open LED fault conditions. The device is housed in a low profile (1mm max height) 5-lead thin SOT23 package for space critical applications.