Linear Technology Introduces Synchronous Step-Down DC/DC Controller

Photocoupler

Linear Technology Corporation (Linear Technology Corporation) introduced dual output high efficiency (up to 95%) synchronous step-down DC / DC controller LTC3869 / -2, provide a good balance between the current when the parallel channel. With its very low 2mV detection voltage maximum mismatch, when the two outputs are connected in parallel, the controller can maintain a current mismatch better than ±4% between channels during steady state and transient conditions. The device's 4V to 38V input range covers a wide range of applications, including most intermediate bus voltages and battery chemistries. The powerful 1.1Ω internal gate driver minimizes switching losses and allows high-power external MOSFETs to generate up to 25A of output current per channel from 0.6V to 12.5V. The device maintains excellent jitter-free performance even when the edge of the switching pulse spans between phases, making it ideal for noise-sensitive requirements. Applications include ASIC and PFGA power supplies, power distribution, network servers, and automotive power systems.

The LTC3869/-2's current mode control and a minimum turn-on time of only 90ns make it ideal for high frequency, high step-down ratio applications requiring a small solution size. Tracking and sequencing optimizes power-up and power-down of multiple power rails. The device operates from a full N-channel MOSFET and produces an output voltage with an accuracy of ±1% over a wide operating temperature range of -40°C to 125°C. The output current is sensed by monitoring the voltage drop across the output inductor (DCR) for maximum efficiency or with a sense resistor. The fixed operating frequency can be set from 250kHz to 780kHz or can be synchronized to an external clock using its internal phase-locked loop (PLL). Other features include a built-in LDO that provides IC power, programmable soft-start, power good signals, and external VCC control.

Among the two package options, the LTC3869's pins are compatible with the LTC3850. The LTC3869 is available in a 4mm x 5mm QFN package, while the LTC3869-2 is available in a SSOP-28 package. The 1,000-piece purchase price is $2.65 per piece. Both versions are available from stock.