MILPITAS, CA – November 4, 2009 – Linear Technology Corporation announces the
LTC3775, a low minimum on-time wide input voltage range synchronous step-down DC/DC
switching regulator controller that drives all N-channel power MOSFET stages. With less
than a 30ns minimum on-time, the LTC3775 is well suited for high step-down ratios. The
4.5V to 38V input range encompasses a wide variety of applications, including most
intermediate bus voltages and battery chemistries. The powerful onboard MOSFET gate
drivers allow the use of high power external MOSFETs to produce output currents up to
20A with output voltages that range from 0.6V to 80% of the input voltage, making the
LTC3775 ideal for automotive, industrial, medical, datacom and telecom
applications.
A constant-frequency, leading edge modulation, voltage mode line feed forward
architecture provides a selectable fixed or phase-lockable (PLL) frequency from 250kHz
to 1MHz. Output current sensing is accomplished by monitoring the current in both the
top-side and bottom-side MOSFET, allowing cycle-by-cycle control of the inductor
current. In addition, the LTC3775 has adjustable soft-start to control the turn-on time
and manage inrush current. Selectable pulse skip mode or forced continuous mode is user
controlled to optimize light load efficiency. The LTC3775 features a precision 0.6V
reference with an accuracy of ±0.75% over a -40°C to 125°C operating temperature
range.
The LTC3775 is available in a thermally enhanced 3mm x 3mm QFN-16 package. The
LTC3775E operates from -40°C to 85°C with the 1000-piece price starting at $1.79 each.
The LTC3775I industrial grade version operates from -40°C to 125°C, with a 1,000-piece
price that starts at $2.09 each. Both versions are available from stock. For more
information, visit www.linear.com.
Summary of Features: LTC3775
- VIN Range: 4.5V to 38V
- VOUT Range: 0.6V to 0.8VIN
- Low Minimum On-Time < 30ns
- Strong Onboard N-Channel MOSFET Driver
- Leading Edge Modulation Voltage Mode Control
- Line Feedforward Compensation
- Sense Resistor or RDS(ON) Current Sensing
- Programmable Cycle by Cycle Current Limit
- Phase-Lockable Fixed Frequency from 250kHz to 1Mhz
- Programmable Soft-Start
- ±0.75% Reference Voltage Accuracy over -40oC to +125oC