 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
MPC823 Datasheet(PDF) 3 Page - Freescale Semiconductor, Inc |
|
||||||||||||||||||||||||||||||
MPC823 Datasheet(HTML) 3 Page - Freescale Semiconductor, Inc |
|
|
3 / 70 page  MPC823 ELECTRICAL SPECIFICATIONS 3 POWER CONSIDERATIONS The average chip-junction temperature, T J , in °C can be obtained from T J = TA + (PD ¥ qJA) (1) where T A = Ambient Temperature, ¥C q JA = Package Thermal Resistance, Junction to Ambient, ¥C/W P D =P INT + PI/O P INT =IDD x VDD , WattsÑChip Internal Power P I/O = Power Dissipation on Input and Output PinsÑUser Determined For most applications P I/O < 0.3 ¥ PINT and can be neglected. If PI/O is neglected , an approximate relationship between P D and TJ is: P D =K Õ (T J + 273¥C) (2) Solving equations (1) and (2) for K gives K = P D ¥ (TA + 273¥C) + qJA ¥ PD 2 (3) where K is a constant pertaining to the particular part. K can be determined from equation (3) by measuring P D (at equilibrium) for a known T A . Using this value of K, the values of P D and TJ can be obtained by solving equations (1) and (2) iteratively for any value of T A. Layout Practices Each VCC pin on the MPC823 should be provided with a low-impedance path to the boardÕs supply. Each GND pin should be provided with a low-impedance path to ground. The power supply pins drive distinct groups of logic on chip. The VCC power supply should be bypassed to ground using at least four 0.1 mF bypass capacitors located as close as possible to the four sides of the package. The capacitor leads and associated printed circuit traces connecting to chip VCC and GND should be kept to less than half an inch per capacitor lead. A four-layer board that employs two inner layers as VCC and GND planes should be used. All output pins on the MPC823 have fast rise and fall times. Printed circuit (PC) trace interconnection length should be minimized in order to minimize undershoot and reflections caused by these fast output switching times. This recommendation particularly applies to the address and data busses. Maximum PC trace lengths of six inches are recommended. Capacitance calculations should consider all device loads as well as parasitic capacitances due to the PC traces. Attention to proper PCB layout and bypassing becomes especially critical in systems with higher capacitive loads because these loads create higher transient currents in the VCC and GND circuits. Pull up all unused inputs or signals that will be inputs during reset. Special care should be taken to minimize the noise levels on the PLL supply pins. Freescale Semiconductor, Inc. For More Information On This Product, Go to: www.freescale.com |
Similar Part No. - MPC823 |
|
Similar Description - MPC823 |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
