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 delivers up to 95% efficiency. This device is designed to provide excellent current balance between parallel channels, with a maximum mismatch of just 2mV. It ensures a current imbalance of less than ±4% under both steady-state and transient conditions when outputs are connected in parallel. The wide input voltage range of 4V to 38V makes it suitable for various applications such as intermediate bus voltages and battery systems.

The LTC3869/-2 features a powerful 1.1Ω internal gate driver, which helps reduce switching losses and allows high-power external MOSFETs to deliver up to 25A per channel from 0.6V to 12.5V. Its jitter-free performance is ideal for noise-sensitive environments, even when switching pulses span across different phases. This makes it an excellent choice for power supplies in ASICs, FPGAs, network servers, and automotive systems.

With current mode control 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 to optimize power-up and power-down sequences for multiple power rails. The device operates using full N-channel MOSFETs and maintains an output accuracy of ±1% over a wide temperature range of -40°C to 125°C.

The output current can be monitored either through the DCR (direct current resistance) of the output inductor 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 an integrated LDO for IC power, programmable soft-start, power-good signals, and external VCC control.

The LTC3869 is available in a compact 4mm x 5mm QFN package, while the LTC3869-2 comes in a SSOP-28 package. Both versions are pin-compatible with the LTC3850, making them easy to upgrade. The unit price for a 1,000-piece order is $2.65, and both are available from stock. For more details, visit the official website.