Linear Technology Introduces Dual Synchronous Step-Down DC/DC Controller

Photocoupler

Linear Technology Corporation has launched the LTC3869/-2, a dual-output, high-efficiency synchronous step-down DC/DC controller that achieves up to 95% efficiency. This device is designed to provide excellent current balance between parallel channels, with a maximum mismatch of just 2mV and a current imbalance of less than ±4% under both steady-state and transient conditions. The wide input voltage range of 4V to 38V makes it suitable for a variety of applications, including intermediate bus voltages and different battery chemistries.

The LTC3869/-2 features a powerful 1.1Ω internal gate driver that minimizes switching losses, enabling high-power external MOSFETs to deliver up to 25A per channel from 0.6V to 12.5V. Its jitter-free performance ensures stable operation even when the switching pulse edges span across phases, making it ideal for noise-sensitive environments such as ASIC and FPGA power supplies, network servers, and automotive systems.

With a current mode control architecture and a minimum turn-on time of only 90ns, the LTC3869/-2 is well-suited for high-frequency, high-step-down ratio applications where space is limited. It supports tracking and sequencing for multiple power rails, ensuring smooth power-up and power-down sequences. The device operates using full N-channel MOSFETs and maintains an output accuracy of ±1% over a broad temperature range of -40°C to 125°C.

The output current can be monitored either through the voltage drop across the output inductor (DCR) for maximum efficiency or via a sense resistor. The fixed operating frequency can be set between 250kHz and 780kHz, or synchronized with an external clock using an internal PLL. Additional features include a built-in LDO for IC power, programmable soft-start, power-good signals, and external VCC control.

Two package options are available: the LTC3869 is offered in a compact 4mm x 5mm QFN package, while the LTC3869-2 comes in a SSOP-28 package. Both versions are compatible with the LTC3850 pinout, offering flexibility for design transitions. The unit price for 1,000 pieces is $2.65 each, and both variants are currently in stock. For more details, visit the official website or contact your local distributor.