500mA, 1.25MHz Synchronous Boost Regulator Features Output Disconnect and Soft-Start in a 2mm × 2mm DFN Package
Linear Technology announces the LTC3427, a 1.25MHz, current mode, synchronous boost DC/DC converter with true output disconnect, inrush current limiting and integrated soft-start capability packaged in a 2mm × 2mm DFN-6. Its internal switches provide a 500mA current limit (min) and deliver output voltages as high as 5.25V from an input voltage range of 1.8V to 5V, making the device compatible with both Li-Ion and dual cell alkaline/NiMH applications. The LTC3427 delivers up to 200mA of continuous output current (at 3.3V) from dual alkaline cells. Its synchronous rectification enables efficiencies of up to 94%. Also, its 1.25MHz constant switching frequency minimizes switching noise and enables the use of a tiny low cost inductor and capacitors. The combination of a 2mm × 2mm DFN and tiny externals provides a very compact, low profile solution footprint required in battery powered handheld applications.
The LTC3427 uses internal switches with an RDS(ON) of only 0.52 Ω N-Channel) and 0.57 Ω (P-Channel) to deliver efficiencies as high as 94%. The device's true output disconnect feature allows the output to be completely disconnected in shutdown. It also limits the inrush of current during start-up, minimizing surge currents seen by the input supply. Additional features include anti-ringing control, short-circuit protection, programmable soft-start, and thermal protection. The LTC3427 is ideal for boost applications requiring up to 200mA of output current, and where a small solution size and maximum battery run-time are defining factors.
LTC3427EDC is available from stock in a 6-lead DFN package. 1,000-piece pricing starts at $1.75 each.
Summary of Features: LTC3427EDC
- High Efficiency: Up to 94%
- 3.3V at 200mA from Two Alkaline Cells
- 5V at 200mA from a Single Li-Ion Cell
- Inrush Current Limiting and Soft-Start
- Output Disconnect in Shutdown
- 1.8V to 5V VIN Range
- 1.8V to 5.25V VOUT Range
- 1.25MHz Fixed Frequency, Low Noise PWM
- Internal Synchronous Rectifier
- Logic Controlled Shutdown (<1uA)
- Anti-Ringing Control Minimizes EMI
- Tiny External Components
- Short-Circuit Protection
- Low Profile (0.75mm × 2mm × 2mm) DFN Package
Editor's Contact Information
- Doug Dickinson