Datasheet

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6.0 DP83843 Application
6.1 Typical Node Application
Figure 22 illustrates a typical implementation of a 10/100
Mb/s node application. This is given only to indicate the
major circuit elements of such a design. It is not intended to
be a full circuit diagram. For detailed system level applica-
tion information please contact your local National sales
representative.
6.2 Power And Ground Filtering
Sufficient filtering between the DP83843 power and ground
pins placed as near to these pins as possible is recom-
mended. Figure 23 suggests one option for device noise fil-
tering including special consideration for the sensitive
analog power pins.
6.3 Power Plane Considerations
The recommendations for power plane considerations pro-
vided herein represent a more simplified approach when
compared to earlier recommendations. By reducing the
number of instances of plane partitioning within a given
Figure 22. Typical Implementation of 10/100 Mb/s Node Application
TXD0 (31)
TXD1 (30)
TXD2 (29)
TXD3 (28)
TX_ER (24)
TX_EN (25)
TX_CLK (33)
MDC (35)
MDIO (34)
RXD0 (15)
RXD1 (14)
RXD2 (13)
RXD3 (12)
RX_ER (19)
RX_DV (20)
RX_CLK (18)
CRS/
SYMBOL (22)
COL/FXEN (21)
AN0 (4)
AN1 (3)
X1 (9)
X2 (8)
THIN/REPEATER (63)
RESET (1)
SPEED10 (5)
SERIAL10 (69)
(74) TPTD+
(73) TPTD-
(67) TPRD+
(65) TPRD-
(78) TXAR100
(43) FXTD+/AUITD+
(44) FXTD-/AUITD-
(50) FXRD+/AUIRD+
(49) FXRD-/AUIRD-
(48) FXSD+/CD+
(47) FXSD-/CD-
(60) TWREF
(61) BGREF
(66) VCM_CAP
(42) LED_COL/PHYAD0
(41) LED_TX/PHYAD1
(40) LED_RX/PHYAD2
(39) LED_LINK/PHYAD3
(38) LED_FDPOL/PHYAD4
NC (2)
NC (55) NC (56) NC (58) NC (59) NC (62)
RX_EN (23)
DP83843
33pF
33pF
25MHz Xtal
50ppm
Active High Reset
Input (500us min)
GND
GND
NC
Floating configures
the device for full
Auto-Negotiation
NC
NC
10KΩ
VDD
Management
{
Receive
{
Transmit
MII
MII
10KΩ
1.5KΩ
NC
NC NC NC NC NC
NC
NC
NC
NC
NC
NC
NC
49.9 Ω
TBD
This cap is an optional component for
control of transmit transition time. An
RJ45-8
49.9Ω 49.9Ω
0.1uF
4.87KΩ
TWAGND
GND
TW_AVDD
directly to the
This point should be tied
GND
V
CC
GND
VDD
1KΩ
1KΩ
1KΩ
1KΩ
1KΩ
10KΩ
10KΩ
10KΩ
10KΩ
10KΩ
This configuration results
in a PHY address of 00001
0.0033uF
TW_AVDD power pin
69.8KΩ
inital value of 10pF is suggested.
GND
Optional 10pF Cap
connected to the center
tap of the receive
transformer
49.9 Ω
GND
Optional 10pF Cap
connected to the center
tap of the transmit
transformer
--TX+
--TX-
100pF
GND
49.9Ω
3kV
--RX+
--RX-
GND
100pF
49.9Ω
3kV