LT1937ES5#TRMPBF

LT1937 is a step-up DC/DC converter specifically designed to drive white LEDs with a constant current. This device can drive two, three or four LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. This device switches at 1.2MHz, allowing the use of tiny external components. The output capacitor can be as small as 0.22µF, saving space and cost versus alternative solutions. A low 95mV feedback voltage minimizes power loss in the current setting resistor for better efficiency. It is widely used in application such as cellular phones, PDAs, handheld computers, digital cameras, MP3 players, GPS receivers etc.

• Inherently matched LED current
• Maximum duty cycle is 90% typical
• Drives upto four LEDs from a 3.2V supply
• Drives upto six LEDs from a 5V supply
• Uses tiny 0.03inch tall inductors
• Feedback voltage is 95mV typical
• Supply current is 1.9mA typical
• Switch VCESAT is 350mA typical at (ISW = 250mA)
• Operating temperature is -40°C to 85°C
• Package style is 5-lead plastic TSOT-23

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party