For many years, semiconductor manufacturers specializing in power management have been striving to meet the ever-evolving demands of end-system users. With the increasing functionality of portable electronic products, there is a growing need for peak performance while maintaining compact physical dimensions. Although the battery industry is making significant strides in developing advanced battery technologies that surpass traditional nickel-cadmium (NiCd) batteries, these innovations still fall short of fulfilling the energy demands of next-generation portable devices. Consequently, designers must explore novel approaches in low-power circuit design to maximize efficiency in portable applications. Components represent a significant portion of the power budget in portable devices, highlighting the necessity for semiconductor manufacturers to continuously innovate in order to reduce the overall power consumption of portable products.
Taking mobile phones as an example, one effective method to reduce power consumption is by lowering the operating voltage of critical components such as analog and digital baseband chips. When the DSP or microprocessor is not operating at its maximum capacity, the core supply voltage can be decreased along with the clock frequency. Numerous modern low-power applications employ this strategy to optimize system efficiency. The formula PC ~ (VC)^2 * F outlines the power consumption of a DSP core, where PC represents the core power consumption, VC is the core voltage, and F denotes the core clock frequency. By reducing the clock frequency, power consumption decreases, and further reductions in the core supply voltage lead to even greater savings.
What role can advanced silicon and packaging technologies play in this context? High-performance portable devices present complex challenges in terms of design. This discussion will focus on low-voltage power switching MOSFETs, examining how recent breakthroughs in silicon technology have influenced the power requirements of such devices. To fully grasp the implications of these advancements, it is essential to first understand several key parameters of power MOSFETs.
The on-resistance (rDS(on)) of the channel is influenced by both lateral and longitudinal electric fields within the channel. The channel resistance is primarily determined by the difference between the gate-to-source voltage. Once the VGS surpasses the threshold voltage (VGS(th)), the FET starts conducting. A switch ground point is often required for various operations. The resistance of the power MOSFET channel depends on its physical dimensions, calculated using the formula R = L / A, where Ï is the resistivity, L is the channel length, and A is W x T, representing the cross-sectional area of the channel.
In a standard FET structure, L and W are defined by the device's geometry, while the channel thickness T is the distance between the two depletion layers. The position of the depletion layer changes with variations in the gate-source bias voltage or the drain-source voltage. Under the influence of VGS and VDS, when T diminishes to zero, the two opposing depletion layers connect, causing the channel resistance (rDS(on)) to approach infinity.
Figure 1 illustrates the relationship between rDS(on) and VGS characteristics. Region 1 corresponds to cases where the accumulated charge is insufficient to induce reversal. Region 2 indicates sufficient charge to partially reverse the P region and form a channel, although the "space charge" effect remains significant. Region 3 reflects scenarios where the charge is limited, and raising the gate potential does not significantly affect rDS(on).
Figure 1: Relationship between rDS(on) and VGS characteristics
Used Laptops For Sale,Old Laptop For Sale,Used Laptop Price,Refurbished Laptops For Sale
Guangzhou Panda Electronic Technology Co., LTD , https://www.panda-3c.com