ROHM Offers Current Mode Switching Regulators For Point-of-Load Applications
ROHM Semiconductor announced the BD91x series of step-down switching regulators that combine ROHM’s propriety SLLM™ (Simple Light Load Mode) technology with current-mode PWM control to provide what is described as exceptional load regulation and high efficiency at both low- and high-current load conditions.
The company states that the SLLM technique enables BD91x series regulators to seamlessly transfer to / from conventional PWM control depending on load conditions. This dual mode of operation improves the efficiency by 100% to 200% over standard PWM controllers that typically ignore the low-power operating regime. In addition, current mode feedback assures fast response to load changes and prevents operational performance problems or failure in voltage-sensitive devices, especially in circuits with supply voltages of 1.8V or less. Variable point-of-load (POL) requirements are found in a wide variety of applications including set top boxes, digital tuners, LCD displays, portable digital players, wireless LAN modules, personal computers, disk drives, microprocessor power supplies, GPS navigation systems and cell phones.
Benefits of the BD91x Series include: single and dual channel outputs; utput current ratings up to 4.0A; dual-mode (SLLM / PWM) operation assures efficiency over the full range of load conditions; exhibits virtually zero current in stand-by mode; fixed and variable output voltage (set by resistor selection); provides output voltage accuracy of ±1.5 / ±2.0%; RoHS compliant; the regulators incorporate ROHM’s P-channel / N- channel CMOS power output to provide both low on-resistance and low switching losses, while reducing the number and size of external components; the quick response of the current sense / feedback loop to any change in load current reduces the voltage variation by as much as 50%; a full suite of built-in protection circuits including over-current, and over-temperature protection, plus under-voltage lock-out; and small wafer-level packages and small form factor packages optimize pc-board utilization.
"The BD91x regulators represent another series of new devices from ROHM Semiconductor that address the emerging needs of ’green’ product designs," said Kevin Turchin, ROHM Semiconductor Field Application Engineering Manager. "With SLLM technology, system designers can provide longer, problem-free operation of portable devices as well as reduced energy consumption."
The devices are priced at US$ 1.00 – 1.80 (small OEM quantities), with a delivery of 12 weeks ARO.
