Motore di ricerca datesheet componenti elettronici |
|
FAN2001 Scheda tecnica(PDF) 2 Page - Fairchild Semiconductor |
|
FAN2001 Scheda tecnica(HTML) 2 Page - Fairchild Semiconductor |
2 / 3 page AN-42036 APPLICATION NOTE 2 REV. 1.00 4/05/05 controller, power and battery management, and RF transceiver. Such a system is shown in Figure 3 with a general scheme of a “star” ground connection. Ideally, all grounds would converge on the main star and a single point ground reference would be generated at that location. It is physically difficult to bring all the traces on a board to a physical location and make contact at a mathematical point to avoid current generated interference. Therefore, the main star might be broken into sub-stars. This shifts the burden to coupling signals from one star to another, which have slightly different, time variable ground reference potentials. Signal coupling between different blocks would have to be differential to avoid all ground problems. Figure 3. Star Ground Connection for a Cell Phone FAN2011 and FAN2001 Regulators The FAN2011 and FAN2001 series of regulators uses a current mode control loop with a fast transient response that ensures excellent line and load regulation. A star ground connection ensures that the highest performance is achieved. The local ground plane for the switching regulator is shown in Figure 4. Figure 4. Star Ground Connection for High Performance DC-DC Converters To benefit from the high performance of the FAN2011/ FAN2001 families of regulators, care must be taken designing the PCB layout. The high ground current paths are identified in Figure 4 by bolded lines. The voltage feedback signal, internally connected to an error amplifier, is sensitive to noise and the resistors must be routed separately from the high current paths. If large ground noise is coupling into the feedback signal the device may become unstable and depending on the noise magnitude, the output voltage will be out of regulation. The internal reference of the device is connected to AGND pin. This pin should also be routed separately from the high current paths directly into the “star.” Any DC offset introduced into the analog ground pin will affect the load regulation and consequently the regulator's DC output voltage accuracy. An optimum PCB layout for the FAN2011 family is shown in Figure 5. Figure 5. PCB Layout Switching Regulator FAN2001 Positive Supply Distribution Local Ground Plane Main Star Analog Baseband Digital Baseband RF Transceiver Audio Amplifier Local Ground Plane LCD Controller CCD/CMOS Camera Memory & I/O ports FB PGND SW PVIN VIN N/C AGND FAN2011 Cin VCC L Cout R2 R1 High ground current paths Composite Top Layer Bottom Layer |
Codice articolo simile - FAN2001 |
|
Descrizione simile - FAN2001 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEETIT.COM |
Lei ha avuto il aiuto da alldatasheet? [ DONATE ] |
Di alldatasheet | Richest di pubblicita | contatti | Privacy Policy | scambio Link | Ricerca produttore All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |