4A, 4MHz, Synchronous Step-Down Regulator in 3mm × 5mm QFN
The LTC3614 is a high efficiency synchronous buck regulator from Linear Technology that incorporates a constant frequency, current mode architecture capable of switching frequencies up to 4MHz. Low resistance internal switches allow the LTC3614 to deliver up to 4A of continuous output current from a 3mm × 5mm QFN package, and its low dropout operation allows the output voltage to range from 0.6V to just millivolts below VIN. The LTC3614 operates over an input voltage range of 2.25V to 5.5V, making it ideal for single cell Li-Ion applications as well as 3.3V or 5V intermediate bus systems. Its switching frequency is user programmable from 300kHz to 4MHz, enabling the use of tiny, low cost capacitors and inductors.
The LTC3614 uses internal switches with RDS(ON) of only 25mΩ and 35mΩ to deliver efficiencies of up to 95%. Burst Mode® operation reduces no-load quiescent current to only 75µA, maximizing both light-load efficiency and run time in battery-powered applications. An adjustable Burst Mode clamp enables designers to optimize light load efficiency. For applications requiring the lowest possible noise, the LTC3614 can be configured to run in either pulse-skipping or forced continuous mode, reducing noise and potential RF interference. Additionally, programmable switching slew rates can further reduce potential noise concerns. The LTC3614 also offers tracking capability as well as a DDR memory mode in which the device can source/sink ±3A. Additional features include optional active voltage positioning, a Power Good voltage monitor, external synchronization capability and thermal protection.
The LTC3614EUDD is available in a 3mm × 5mm QFN-24. Pricing starts at $3.45 each in 1,000-piece quantities. An industrial grade version, the LTC3614IUDD is guaranteed to meet specifications over the –40ºC to 125ºC operating junction temperature range and is priced at $4.06 each in 1,000-piece quantities. For more information, visit www.linear.com.
Summary Features LTC3614
- 4A Output Current
- 2.25V to 5.5V Input Voltage Range
- Output Voltage Range: 0.6V to VIN
- Adjustable Switching Frequency: Up to 4MHz
- Low Output Ripple (<20mVPK-PK) Burst Mode® Operation: IQ = 75µA
- ±1% Output Voltage Accuracy
- High Efficiency: Up to 95%
- Programmable Slew Rate on SW Node Reduces Noise & EMI
- Optional Active Voltage Positioning (AVP) with Internal Compensation
- Selectable Pulse-Skipping/Forced Continuous /Burst Mode Operation with Adjustable Burst Clamp
- Programmable Soft-Start
- Inputs for Start-Up Tracking or External Reference
- DDR Memory Mode, IOUT = ±3A
- Available in a 24-Pin 3mm × 5mm QFN Thermally Enhanced Package
4A, Synchronous Step-Down DC/DC Converter Capable of up to 4MHz Switching Frequency
Editor's Contact Information
- Doug Dickinson