400mA MicroPower Synchronous Step-up Regulators with Output Disconnect in an SC70
Linear Technology announces the LTC3525-3.3 and LTC3525-5, 400mA synchronous step-up DC/DC converters with true output disconnect and inrush current limiting in SC70 packages. They operate from an input voltage range of 1V to 4.5V, making them ideal for single- and multicell alkaline/NiCd/NiMH, as well as Li-Ion applications. The LTC3525-3.3 offers a fixed 3.3V output whereas the LTC3525-5 has a fixed 5V output. The LTC3525-3.3 can deliver up to 140mA of continuous output current from dual AA alkaline cells. The LTC3525-5 can deliver up to 175mA at 5V from a 3V input. Both devices use synchronous rectification to enable efficiencies of up to 95%. Their Burst Mode® operation lowers quiescent current to only 7uA, providing maximum battery run-time in handheld applications. The combination of an SC70 package plus only 3 tiny externals provides small solution footprints as required in space constrained applications.
The LTC3525-3.3 and LTC3525-5 both incorporate internal switches with an RDS(ON) of only 0.5 Ω (N-Channel) and 0.8 Ω (P-Channel). Combined with their unique Adaptive Power Control switching topology, they deliver efficiencies greater than 90% to loads varying from 1mA to 100mA. Both parts offer output disconnect and inrush current limiting to restrict the current during start-up, minimizing surge currents seen by the input supply. Additional features include anti-ringing control, short-circuit protection and thermal protection. The LTC3525-3.3 and LTC3525-5 deliver ideal solutions for boost applications requiring up to 150mA of output current, and where a small solution size and maximum battery run-time are defining factors.
Both the LTC3525ESC6-3.3 and the LTC3525ESC6-5 are available from stock in a 6-Lead SC70 package. 1,000-piece pricing starts at $1.75 each.
Summary of Features: LTC3525ESC6-3.3/5
- Up to 95% Efficiency
- Output Disconnect & Inrush Current Limit
- Fixed Output Voltages of 3.3V or 5V
- Delivers 60mA at 3.3V from a 1V Input, or 140mA at 3.3V from a 1.8V Input
- Delivers 175mA at 5V from a 3V Input
- Burst Mode Operation: IQ = 7uA
- Only Three External Components
- 1V to 4.5V Input Range
- <1uA Shutdown Current
- Short-Circuit and Overtemperature Protection
- Very Low Solution Footprint Profile of 1mm
- Tiny 6-Pin SC-70 Package
Editor's Contact Information
- Doug Dickinson