LTC3440EDD#TRPBF

LTC®3440 is a high efficiency, fixed frequency, buck boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for single lithium-ion, multicell alkaline or NiMH applications where the output voltage is within the battery voltage range. The device includes two 0.19ohm N-channel MOSFET switches and two 0.22ohm P-channel switches. Switching frequencies up to 2MHz are programmed with an external resistor and the oscillator can be synchronized to an external clock. Quiescent current is only 25µA in burst mode operation, maximizing battery life in portable applications. Other features include a 1µA shutdown, soft-start control, thermal shutdown and current limit. Typical applications are palmtop computers, handheld instruments, MP3 players, digital cameras.

• Burst mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high
• If the MODE/SYNC pin has either a clock or is driven low, then fixed frequency switching is enabled
• Fixed frequency operation with battery voltages above, below or equal to the output
• Synchronous rectification: up to 96% efficiency
• No schottky diodes required (VOUT <lt/> 4.3V), VOUT disconnected from VIN during shutdown
• Synchronizable oscillator, burst mode enable control
• Input operating range from 2.5 to 5.5V (TA=25°C. VIN=VOUT=3.6V, RT=60k)
• Feedback input current is 50nA (VFB=1.22V)
• 10-lead plastic DFN package
• Temperature rating range from -40°C to 85°C

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