The KT600 Chipset as Important Parts of Motherboard - Essay Example

The KT600 Chipset Chipsets are important parts of motherboards in any PC. Chipset may be defined to be a group of chips that facilitates and integrates all components of a PC as the infrastructure of the PC. Mainly, chipsets consist of two sets of major microchips. These are the Northbridge and Southbridge microchips. The development and advancement in chipset technologies has led manufacturers to adopt different designs in chipset manufacturing and layout. Currently, some PC manufacturers have adopted a built in memory controller that facilitates taking the job from the Northbridge, while others have incorporated both the Northern and southern bridges in the same chip. In this article, the KT600 chipset from Via Technologies will be investigated with its operations, configurations and the layout demonstrated to understand the operations and configuration of the chipset (Via Technologies, 2012). The general arrangement of the KT600 chipset in relation to other PC components (Source: DragonByte technologies, 2012) The above chipset consist of the north and south bridge as shown in the diagram above. In the KT600 chipset, the Northern bridge handles all data from graphic ports, the AGP, or PCI express, and then from memory consisting of Front Side Bus, FSB (Via Technologies, 2012). Although the two chips are essential from the chipset, mostly, the Northern chipset handles most of the essential tasks, which include connection between the main memory bank and he CPU. On the other hand, the Southern bridge is responsible for data from PCIx1 slots and may even have some integrated components such as audio or onboard graphics. As shown on the figure above, the North and South bridges have different chips names though they are often paired with the same opposite bridges, to be referred to with the collective name of a chipset. The diagram shows all the components of a PC, and how these are connected to either the north or south bridges of the KT600 chipset. The main functions of the above chipset are to manage data throughout the PC. Data is transported throughout the PC through a bus. The bus is responsible for carrying data to its right location via the chipset. However, the Backside Bus (BSB); the bus between the cache memory and the CPU does not follow this rule. Some PCs today may have the cache memory, which makes it not necessary to go through the chipset when carrying this information in the PC. The BSB is however different from the main memory bus in that it only dictates the speed between the cache memory and the CPU. The memory bus speed is usually a different bus, with the ability to change the speed independently. Apart from the BSB the other buses go through the chipset to get required direction where to take the data. This implies the huge amount of data that goes through the chipset requires it to be up to speed. Speed is one of the important aspects that have to be considered when considering the above chipset, as poor choice of speed may severely hamper the performance of a computer. For example, with the advanced Fast stream 64 DDR400 Memory Controller on the VIA Apollo KT600 interweaves used together with the 400MHZ FSB, this results to a perfectly balanced subsystem that greatly reduces data latency and enhances searing performance from the latest processors, such as the AMD Athlon XP Processor. Moreover, the KT600 supports the AGP8X, which offers the chipset maximum performance from one of the most powerful graphic controllers (Via Technologies, 2012). A Figure of Gates diagram for KT600 Chipset The chipset operates according to the logic diagram portrayed above. The High Voltage Gate Drivers are strategically designed and arranged to drive both high and the low side N channel MOSFETs in a half bridge synchronized configuration (Texas Instruments, 12). The floating high speed driver can operate with a supply voltage of up to 100V. Moreover, the A version provides a full 3A of gate drive, while the B and C provide the 2A and 1A versions respectively (Texas Instruments, 2012). The outputs are controlled independently with the CMOS input thresholds (LM5100a/B/C) or the TTL input thresholds, which is the LM5101A/B/C. with the above, an integrated high voltage diode operates to charge high side gate drive capacitor (Texas Instruments, 2012). The above simplified diagram portrays that a robust shifter has to operate at higher speeds while at the same time consuming lower power and offering clean level transitions from the control logic to the high side gate driver. In addition, an under-voltage provision is provided to lockout on both the low and high side power rails as observed in the diagram above. The design allows connection to the positive terminal of the bootstrap capacitor to HB, while the negative terminal is connected to HS (Texas Instruments, 2012). Moreover, the high side gate MOSFET is connected to a low inductance path. The bootstrap capacitor negative terminal is also connected, as well as the source of the high side MOSFET. The chipset contains a digital micromirror device, which is an electrical input and optical output memory. Each micromirror of the digital micromirror device can be deflected at +/- 12 degrees from a hinged axis. This deflection angle of each micromirror can be controlled by changing the binary state of the respective CMOS memory cell proceeded by a setoff Mirror Reset pulse (Texas Instruments, 2012). The DMD Micromirror Driver compactly integrates the analog control required in blocking the DMD micromirrors into a single chip, the analog control that is required to close the DMD micromirrors. Generally, as the above gates diagram portray, the performance of high and low side gate drivers may not be possible without taking the necessary measures in the circuit board layout. For example, as Texas Instruments (11) explains, low ESR capacitors have to be connected close enough to the IC, which is between the HS and HB pins in supporting the high peak currents drawn from the VDD in turn-on of the external MOSFET. In addition, the design ensures that in preventing large voltage transients at the drain of the top MOSFET, a capacitor of low ESR electrolyte may be connected between MOSFET drain and the ground (Texas Instruments, 12). In most case, when designing ground connections, the first priority should be to confine the high peak currents responsible for charging and discharging the MOSFET gate into a minimal physical area. This decreases the loop inductance, while at the same time minimizing noise issues on the MOSFET gate terminals. Therefore, as Texas Instruments explains, the MOSFETs have to be placed as close to the gate driver as possible. In addition, Texas Instruments (12) argues that the high current includes the bootstrap capacitor, bootstrap diode, and the local ground referenced bypass as well as the low side MOSFET body diode. The bootstrap capacitor has to be charged on cycle basis through the bootstrap diode from the ground referenced VDD bypass Capacitor (Texas Instruments, 12). This recharging occurs at short time intervals and involves high peak currents, in ensuring reliability in its operations; there is a need to minimize the loop length area on the circuit board. The above chipset in gate design provides necessary gate drive signs in fully controlling the grounded source low side power deice, together with floating source high side power device. Moreover, the above chips provides a negative going off –state gate drive signals for better turn off of IGBTs, or power MOSFETs and a reliable system logic compatible status fault output, FLT, in indicating overcurrent, or desaturation as well as the under voltage in the chipset. (Texas Instrument, 13).in case of a status fault, both the chipsets keep their respective gate drive outputs off. The actual work of a chipset such as the above chipset KT600 is to communicate between all the components of a PC, meaning the chipset acts as the infrastructure in a PC. It has numerous components and makes various interfaces available for connecting other additional components such as the PCI, USB, IDE and others. The chipset contains two units as shown. These are the North and South bridges, as it is difficult to integrate all functions into a single chip, making the two chips to carry different functions in facilitating operations of the PC. Work Cited Texas Instruments. 3A, 2A and 1A High Voltage High-Side and Low-Side Gate Drivers. 2012, March 12. http://www.ti.com/lit/ds/symlink/lm5101b.pdf 15th May 2012 VIA Technologies. VIA KT600. VIA, 2012. http://www.via.com.tw/en/products/chipsets/k7-series/kt600/index.jsp 15th May 2012 “KT600-ALX Main Board Manuals” 2003, July 28. http://xfxstorage.com/Support/Manuals/VIA/KT600-ALX%20MANUAL.pdf 15th May 2012 Read More