A highly-integrated general-purpose power management solution for systems requiring multiple low voltage power supplies has been developed by Linear Technology Corporation.
The company’s LTC3375 features eight independent 1A channels with I2C control, flexible sequencing and fault monitoring in a compact QFN package.
The devices has a section of enabling features including eight internally compensated, high efficiency synchronous step-down regulators plus a high voltage always-ON 25mA LDO controller.
Each buck regulator has its own independent 2.25V to 5.5V input supply and an output voltage range of 0.425V to VIN. As the device has a pushbutton ON/OFF/RESET control, power-on reset and watchdog timer this results in flexible and reliable power-up sequencing and system monitoring.
The devive is equipped with a programmable and synchronisable 1MHz to 3MHz oscillator with a 2MHz default switching frequency.
For improved capability it offers quiescent current at just 16µA with all DC/DCs off, saving battery run time.
As a result of the combination of features designed into this device, It is ideal for a wide variety of multichannel applications including industrial, automotive and communications systems.
The device has buck DC/DCs that can be used independently or connected in parallel to achieve higher output currents up to 4A per output with a single shared inductor. Up to four adjacent regulators can be combined, resulting in 15 different possible output configurations.
Adjacent buck regulators can be combined in a master-slave configuration by connecting their VIN and SW pins together, and connecting the slave bucks’ FB pin(s) to the input supply. All of the switching regulators are internally compensated and need only external feedback resistors to set the output voltage.
Alternatively, the output voltages can be set via I2C. The switching regulators offer two operating modes: Burst Mode® operation (power-up default mode) for higher efficiency at light loads, and forced continuous PWM mode for lower noise at light loads. The I2C interface can be used to select mode of operation, phasing, feedback regulation voltage and switch slew rate.
The bucks have forward and reverse current limiting, soft-start to limit inrush current during start-up, short-circuit protection and slew rate control for lower radiated EMI. Other features include a die temperature monitor output (readable via I2C) that indicates internal die temperature, and an overtemperature (OT) warning function, which warns the user that the die temperature is approaching the OT threshold.
Linear Technology Corporation