APPLICATION NOTE RTL00C(L) / RTL0S- / RTL0SB(L) -pin (L)QFP COMPATIBLE BOARD DESIGN GUIDELINES (Rev..0; 00//)
TABLE OF CONTENTS INTRODUCTION DESIGN CONSIDERATION... POWER DISTRIBUTION CIRCUITRIES.. RJ JACK & MAGNETICS INTERFACE LED... 0 HISTORY OF REVISION
INTRODUCTION This application is written to help board layer designer to create a PCB layout which will be able to accept both Realtek s 0/00 Fast Ethernet Chip (RTL00C(L)) and Realtek s Gigabit Single Chip solution (RTL0S- & RTL0SB(L)). All three chips packages will be sharing similar pin assignment in order to achieve Pin Compatibility feature that means all three chips will be able to use a common footprint so that any one of these ICs can be placed on the same PCB layout. All three Chip packages have been defined as pins (L)QFP appearance. Due to the functional differences, the particular surrounding components are also required to populate with corresponding IC. Through this application note, the information between these three designs consideration will be highlighted and discussed to help the board layer designer to achieve the pin-compatible layout in the shortest period. DESIGN CONSIDERATIONS Several Major points must be considered while designing a PCB that will accept all three RTL00C(L), RTL0S- & RTL0SB(L) ICs. Those points have been categorized as below and been detailed in the following chapters. - Power Distribution Circuitry - RJ Jack & Magnetics Interfaces - LED
Power Distribution Circuitries: Due to the different Fabrication processes (0. micron for RTL00C(L); 0. micro for RTL0S-; 0. micro for RTL0SB(L)), the power requirement for all three chips are slightly different from each due to smaller fabrication process requires smaller core voltage (i.e..v &.V for RTL00C(L);.V,.V &.V for RTL0S-;.V,.V &.V for RTL0SB(L)). Moreover, the power is distributed as needed to various parts of chip and differential pair terminations (ex. ). Details of placing correct decoupling capacitors & beads on each application have been shown in the following Figures.
U is used for RTL00C application, U and Q are used for RTL0S(B) application. U VCC VCC Vsby Vcc Vout Vaux CMPWR0 * C0 to C are for U RTL0S(B)/RTL00C pins, such as,,,,, 9 and 0. VAUX C90 C9 U Vsby Vcc Drive Vout S G Q VCC D FDNP L C uf C C0 C C C C C C At RTL00C application, remove R and L,keep L0. uf uf CMPWR0 At RTL00C application, Q and U must be removed. L * C and C are for U RTL0S(B) pins, such as 0 and 0. C C R 0 C L0 V_P * C is for U RTL0S(B)/RTL00C pin. *For RTL00C(L) application, both L & L0 need change to 0 ohm instead. Q CTRL CTRL U SPX90-. IN OUT SB L At RTL00C application, keep L. At RTL0S(B) application, remove L. C ADJ C C C C C C.uF 0uF R 0 R 0 * C to C are for U RTL0S(B)/RTL00C pins, such as,,, and 0. C CTRL U0 IN C Q9 CRTL AMS ADJ OUT Q CTRL SB9 SB R C C9 _A _A L C *For RTL00C(L) application, both L & L0 need change to 0 ohm instead. C C9 C0 C C C C C 0uF uf R9 C0 0uF C At RTL00C application, Q9 and U0 must be removed. CON AUXV CONN * C to C are for U RTL0S(B)/RTL00C pins, such as,,,,,, 99, 0 and. V_P RTL00C.AVDD.AVDD.VDD RTL0S / RTL9S.AVDD.AVDD.AVDD.VDD RTL0SB / RTL9SB.AVDD.AVDD.AVDD.AVDD.VDD _A.AVDD.AVDD Fig. 0/00 BASE-T Fast Ethernet Application Circuit Power : RTL00C(L)
U and Q are used for RTL0S application. VCC VAUX C90 uf C9 uf VCC U Vsby Vcc Vout Vaux CMPWR0 U Vsby Vcc Drive Vout CMPWR0 Q or U is used for RTL0S application. The.V power can be supplied by external.v regulator, U. Or by internal regulator in RTL0S and external BJT, Q. S G Q VCC D FDNP L C uf C * C0 to C are for U RTL0S/RTL00C pins, such as,,,,, 9 and 0. L C0 C * C and C are for U RTL0S pins, such as 0 and 0. C C C C C C R 0 C C At RTL0S application, remove L0 and R, keep L. L0 V_P * C is for U RTL0S pin. CTRL Q CTRL U SPX90-. IN OUT SB L At RTL0S application, remove L. C ADJ C C C C C C.uF 0uF R 0 R 0 If Q9 is used, remove R and keep R at RTL0S application * C to C are for U RTL0S(B)/RTL00C pins, such as,,, and 0. CTRL CRTL Q9 CTRL Q SB9 _A _A U0 IN C C 0uF AMS ADJ OUT R SB C uf C9 L C C C9 C0 C C C C C * C to C are for U RTL0S(B)/RTL00C pins, such as,,,,,, 99, 0 and. R9 If U0 is used, R and R9 can be set to.k and.k to have.v output power at RTL0S application Q9 or U0 is used for RTL0S application. The power can be supplied by external adjustable regulator, U0. Or by internal regulator in RTL0S and external BJT, Q9. RTL00C RTL0S / RTL9S.AVDD RTL0SB / RTL9SB.AVDD V_P.AVDD.AVDD C0 0uF C CON AUXV CONN _A.AVDD.VDD.AVDD.AVDD.VDD.AVDD.AVDD.AVDD.VDD.AVDD Fig. 0/00/000 Gigabit Ethernet Application Circuit Power : RTL0S-
CON U and Q are used for RTL0S application. VCC VAUX C90 uf C9 uf VCC U Vsby Vcc Vout Vaux CMPWR0 U Vsby Vcc Drive Vout CMPWR0 S Q D FDNP Q or U is used for RTL0S application. The.V power can be supplied by external.v regulator, U. Or by internal regulator in RTL0S and external BJT, Q. G VCC L C uf C * C0 to C are for U RTL0S/RTL00C pins, such as,,,,, 9 and 0. L C0 C * C and C are for U RTL0S pins, such as 0 and 0. C C C C C C R 0 C C At RTL0S application, remove L0 and R, keep L. L0 V_P * C is for U RTL0SB pin. Q CTRL CTRL U SPX90-. IN OUT SB L For RTL0SB application, make sure the R(0 ohm) is placed so that V_P is connected to (.V) C ADJ C C C C C C.uF 0uF If Q9 is used for generating.v power source, either R or R is needed. (Do not place both components at the same time). Further more, in this case, U0, R, R9, C, C should be removed as well C 0uF R 0 R 0 CRTL CTRL U0 AMS IN Q9 Q CTRL SB SB9 R C C C9 uf ADJ OUT _A _A L C C C9 * C to C are for U RTL0S(B)/RTL00C pins, such as,,, and 0. C0 C C C C C * C to C are for U RTL0S(B)/RTL00C pins, such as,,,,,, 99, 0 and. R9 If U0 is used to generat.v output for RTL0SB application, R and R9 have to be set to 'Open' and 0 ohm. Further more, in this case, R, R and Q9 should be removed C0 C Either Q9 or U0 can be used for RTL0SB application. The power can be supplied by external adjustable regulator, U0 or by internal regulator in RTL0S with external BJT, Q9. AUXV CONN V_P RTL00C.AVDD.AVDD RTL0S / RTL9S.AVDD.AVDD.AVDD RTL0SB / RTL9SB.AVDD.AVDD.AVDD.AVDD 0uF.VDD.VDD.VDD _A.AVDD.AVDD Fig. 0/00/000 Gigabit Ethernet Application Circuit Power : RTL0SB(L)
RJ Jack & Magnetics Interface The Realtek RTL0S-/ RTL0SB(L) are 0/00/000 BASE-T Gigabit Ethernet Single Chip, but the RTL00C(L) only supports 0/00 BASE-T Fast Ethernet. Therefore, extra differential pairs will be required for interfacing the Magnetics Transformer (i.e. pairs only for RTL00C(L)) while using RTL0S- or RTL0SB(L). These extra differential pairs should be neglected while populating RTL00C(L). Since the PCB interface should be designed for both RTL00C(L) & RTL0S- devices, it is important that the design guidelines as shown below must be followed to ensure the proper operation for both Applications (Fast Ethernet & Gigabit Ethernet). A proper magnetic transformer must be selected carefully, which must have the same footprint for both Fast Ethernet & Gigabit Ethernet applications. One Ideal Example would be Pulse Engineer s H00 (Gigabit Transformer) and H (Fast Ethernet Transformer). Further more, the guideline for PCB routing should be followed as shown in Fig.
R0 0 R0(0 ohm) is reserved for both RTL0S & RTL0SB applications. For RTL00C application, R0 must be removed. C.0uF C.0uF C.0uF C.0uF R R R R9 R R R R 9.9 9.9 9.9 9.9 9.9 9.9 9.9 9.9 CHASSIS_ 9 CON RJ DA DA- DB DC DC- DB- DD DD- 9 0 U TD- TD TCT TD- TD TCT TD- TD TCT TD- TD TCT MX- MX MCT MX- MX MCT MX- MX MCT MX- MX MCT 0 9 MDI0 MDI- MDI0 MDI0- MDI MDI- MDI MDI- MDI MDI- MDI0- MDI MDI MDI MDI- MDI- R R R R Pulse H00/ Pulse H C.0uF C.0uF C0.0uF C9.0uF 000pF/KV C CHASSIS At RTL00C application, use Pulse H At RTL0S- /RTL0SB application use Pulse H00 / H0 / 0. At RTL00C application, remove R, R, R, R, C, C, C, C, C9, and change C0 value from.0uf to. Fig : RJ Jack & Magnetics Interface 9
LEDS LED & R are removed for RTL00C Application LED0 R 0 D LED0 LED R9 0 D LED LED R 0 D9 LED LED R 0 D0 LED For RTL0S-/ RTL0SB applications, all resistors and LEDs must be kept for correct output LED information Fig. LED circuit for 0/00 Fast Ethernet : RTL00C(L) 0
HISTORIES OF REVISION - (0) Rev..0: Initial Release: 00// - (0) Rev..0:. Change PIN assignment from PIN to.. Fix the not correct assignment between RJ and Transformer. - (0) Rev..0:. Add Transformer Part No. for RTL00C(L) application circuit (page, fig ). Remove C9 instead of C0 (keeping C0) for RTL00C(L) application circuit (pag, fig ) - (00) Rev..0. Add Transformer Part No. for RTL0S- application circuit (page, fig) - (0) Rev..0. Add Extra Information regarding RTL0SB(L) to ensure all three ICs can be Co-Layout - (0) Rev..0. Add Extra Information regarding RTL00C(L) power source.v (page, fig)