LM65680

The LM656x0 is a synchronous buck DC/DC converter offered from a family of devices with mitigated interference and noise technology using architecture 1 features (MINT 1) that enable low EMI, high power density, and excellent conversion efficiency. Integrated power MOSFETs with low RDS(on) enable up to 8A of output current across a wide VIN range of 3.5V to 65V.

Phase stackable with synchronized interleaving, the peak current-mode control architecture of the LM656x0 supports accurate current sharing with paralleled phases for higher output currents. AUTO mode enables frequency foldback during light-load operation, giving high light-load efficiency and a no-load input current as low as 2.2µA, which extends operating run-time in battery-powered systems.

A high-side switch minimum on-time of 36ns facilitates large step-down ratios, enabling the direct conversion from 24V or 48V inputs to low-voltage rails for reduced system cost and complexity. The package has several NC pins between critical power pins, which improve the Failure Modes and Effects Analysis (FMEA) result.

The LM656x0 includes several features to simplify compliance with CISPR 11 and CISPR 32 emissions requirements. First, a symmetrical pinout provides excellent input capacitor placement and enables an ultra-low effective value for the power-loop parasitic inductance, which reduces switching losses and improves EMI performance at high input voltage and high switching frequency. A pin-selectable switch-node slew-rate control feature further reduces emissions at high frequencies. To lower input capacitor ripple current and EMI filter size, interleaved operation using a SYNCOUT signal with 180° phase shift works well for cascaded, multichannel or multiphase designs. Resistor-adjustable switching frequency as high as 2.2MHz can be synchronized to an external clock source to eliminate beat frequencies in noise-sensitive applications. Finally, the LM656x0 has dual-random spread spectrum (DRSS), a unique EMI-reduction feature that combines low-frequency triangular and high-frequency random modulations to mitigate disturbances across lower and higher frequency bands, respectively.

Additional features of the LM656x0 include 150°C maximum junction temperature operation, open-drain power-good (PG) indicator for fault reporting and output voltage monitoring, precision enable input for input UVLO protection, monotonic start-up into prebiased loads, dual-input VCC bias subregulator powered from VIN or BIAS, hiccup-mode overload protection, and thermal shutdown protection with automatic recovery.

The LM656x0 comes in a 4.5mm × 4.5mm, thermally enhanced, 26-pin eQFN package with additional pin clearance for increased reliability. Also included are wettable-flank pins to facilitate optical inspection during manufacturing. Leveraging a flip-chip routable leadframe (FCRLF) packaging technique, the LM656x0 with useable current, lifetime reliability, and cost advantages targets applications requiring high power density. The wide input voltage range, low quiescent current consumption, high-temperature operation, cycle-by-cycle current limit, low EMI signature, and small design size provide an excellent point-of-load regulator design for applications requiring enhanced robustness and durability.