NATIONAL Semiconductor, represented by Arrow Electronics , has introduced two new, integrated power management units (PMUs) to its family of designer-friendly, easy-to-use PMUs.
Optimised to power mid-range, quad-output applications, such as low-power FPGAs, microprocessors and DSPs, the LP3906 and LP3905 PMUs each feature two high-efficiency buck regulators and two ultra-low-noise, low-dropout regulators (LDOs).
The high level of integration simplifies system design and increases space efficiency.
National's LP3906 PMU features an I2C compatible interface for programmability. This digital interface provides the flexibility to use the same device for multiple solutions that require different output voltages.
By including dynamic voltage scaling with 96 percent conversion efficiency, the power consumption of the powered device, such as a microprocessor, is reduced, thus maximising the power efficiency of the entire system.
Example applications for these products include powering an embedded processor, in which each switching regulator can drive the core and input/output while each LDO supplies the analogue and peripheral functions.
In FPGA applications, the dual regulators power the core and I/O voltages, and the dual LDOs power the auxiliary voltages that supply the embedded peripherals such as communication engines.
Technical features of the LP3906
Available in a small, 24-pin thermally enhanced LLP package that measures 4mm by 5mm, the LP3906 PMU provides designers with a simple, highly efficient and flexible solution to efficiently drive core I/O and auxiliary power.
It features two integrated 1.5A, high-efficiency buck regulators and two 300mA linear regulators with an I2C compatible interface for programmability.
The dual buck regulators have a dynamically programmable, wide-output voltage range from 0.8V to 3.5V with up to 96 percent efficiency. This high efficiency is accomplished by intelligent automatic switching between PWM and PFM modes.
The dual linear regulators have a dynamically programmable wide output voltage range from 1.0V to 3.5V. The high-speed serial interface for independent control of device functions and settings enables features such as dynamic voltage management, power-up sequencing control and design flexibility.
Technical features of the LP3905
Available in a tiny, 14-pin thermally enhanced LLP package that measures 4mm by 4mm, National's LP3905 PMU contains two integrated, 600mA, high-efficiency buck regulators and two 150mA, ultra-low-noise linear regulators.
The dual buck regulators have a fixed and adjustable output voltage range from 1.0V to 3.3V with up to 90 percent efficiency. The buck regulators feature intelligent automatic switching between PWM and PFM modes to achieve the highest efficiency possible for the entire load range.
When operating in PWM mode, both regulators have a switching frequency of 2MHz, allowing use of small external components. The dual linear regulators have an output voltage range from 1.5V to 3.3V, with low dropout voltage and low output voltage noise.