DP83865DVH National Semiconductor, DP83865DVH Datasheet - Page 83

• Manufacturer Part Number: DP83865DVH
• Description: 10/100/1000BASE-T TRANSCEIVER, SMD
• Manufacturer: National Semiconductor

Specifications of DP83865DVH

• Data Rate: 1000Mbps
• No. Of Ports: 1
• Ethernet Type: IEEE 802.3u, IEEE 802.3z
• Supply Current: 430µA
• Supply Voltage Range: 2.375V To 2.625V, 3.135V To 3.465V
• Operating Temperature Range: 0°C To +70°C
• Interface Type: GMII, MII, RGMII
• Rohs Compliant: Yes
• Leaded Process Compatible: No
• Peak Reflow Compatible (260 C): No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.0 Frequently Asked Questions
in advance what mode the link partner is operating, there
could be conflict if both PHY are operating in Master or
both in Slave mode. It is recommended that under normal
operation, AN_EN is enabled.
7.9 How long does Auto-Negotiation take?
A: Two PHY’s typically complete Auto-Negotiation and
establish 1000 Mbps operation in less than 5 seconds.
1000BASE-T Auto-Negotiation process takes longer than
the 10/100 Mbps. The gigabit negotiation does Next Page
exchanges and extensive line adaptation.
7.10 How do I measure FLP’s?
A: In order measure FLP’s Auto MDIX function must be
disabled. When in Auto MDIX mode the DP83865 outputs
link pulses every 150 s. Note that MDIX pulse should not
be confused with the FLP pulses which occur every 125 s
+/- 14 s. To disable Auto MDIX, AUX_CTL 0x12.15 = 0.
Once Auto MDIX is disabled register bit 0x12.14 specifies
MDIX mode.
straight mode. In crossover mode, the FLP appears on
pins 3-6 of RJ-45 and in straight mode, the FLP appears on
pins 1-2.
7.11 I have forced 10 Mbps or 100 Mbps operation
but the associated speed LED doesn’t come on.
A: Speed LEDs are actually an AND function of the speed
and link status. Regardless of whether the speed is forced
or Auto-Negotiated, there has to be good link for the speed
LEDs to turn on.
7.12 I know I have good link, but register 0x01, bit
2 “Link Status” doesn’t contain value ‘1’ indicat-
ing good link.
A: This bit is defined by IEEE 802.3u Clause 22. It indi-
cates if the link was lost since the last time this register was
read. Its name (given by IEEE) is perhaps misleading. A
more accurate name would have been the “Link lost” bit. If
the actual present link status is desired, then either this
register should be read twice, or register 0x11 bit 2 should
be read. Register 0x11 shows the actual status of link,
speed, and duplex regardless of what was advertised or
what has happened in the interim.
7.13 Your reference design shows pull-up or pull-
down resistors attached to certain pins, which
conflict with the pull-up or pull-down information
specified in the datasheet?
A: The pull-up or pull-down information specified in the pin
description section of the datasheet, indicate if there is an
internal pull-up or pull-down resistor at the IO buffer used
for that specific pin. These resistors are between 25 - 80
k . They will determine the default strap value when the
pin is floating. If the default value is desired to be changed,
an external 2 k pull-up or pull-down resistor can be used.
7.14 How is the maximum package case temper-
ature calculated?
A: The maximum die temperature is calculated using the
following equations:
T
T
J
J
= T
= T
A
C
+ P
+ P
d
d
(
(
JA
c
)
‘1’ for MDIX cross over mode and ‘0’ for
)
(Continued)
83
T
Where:
T
T
P
O
For reliability purposes the maximum junction should be
kept below 120
and the power dissipation is 1.2 watts then the Maximum
Case Temperature should be maintained at:
T
T
7.15 The DP83865 will establish Link in 100 Mbps
mode with a Broadcom part, but it will not estab-
lish link in 1000 Mbps mode. When this happens
the DP83865’s Link LED will blink on and off.
A: We have received a number of questions regarding
inter-operability of National’s DP83865 with Broadcom’s
BCM5400 1000/100 Mbps PHY. National’s DP83865 is
compliant to IEEE 802.3ab and it is also inter-operable with
the BCM5400 as well as other Gigabit Physical Layer prod-
ucts. However, there are certain situations that might
require extra attention when inter-operating with the
BCM5400.
There are two types of BCM5400’s, those with silicon revi-
sions earlier than C5 and those with silicon revisions of C5
and older. There is a fundamental problem with earlier sili-
con revisions of the BCM 5400, whereby the part was
designed with faulty start-up conditions (wrong polynomials
were used) which prevented the Broadcom BCM5400 from
ever linking to an IEEE 802.3ab compliant part.
This problem was observed in early inter-operability testing
at National Semiconductor. A solution was put together that
allows the DP83865 to inter-operate with any IEEE
802.3ab compliant Gigabit PHY as well as with earlier revi-
sions of the BCM5400 that are non compliant. To enter into
this mode of operation you can either pull pin 1
(NON_IEEE_STRAP) high through a 2k
‘1’ to bit 9 of register 0x12.
7.16 How do I quickly determine the quality of the
link over the cable ?
A: Idle error indicates either that the cable length is beyond
the specified limit or the cable plant does not meet the EIA
568 Category V requirements. The Activity LED indicates
the occurrence of idle error or packet transfer. You monitor
the quality of the link by viewing the Activity LED during
idle.
7.17 What is the power up sequence for
DP83865?
A: The DP83865 has two types of power supplies, core
and I/O. Although there has not been revealing of power
up sequence error such as latch up or dead lock, it is rec-
ommended that core power takes precedence over the I/O
power when powering up. 1.8V should be up before 2.5V
and 3.3V. When powering down, I/O takes precedence
over core. 2.5V and 3.3V should be turned off before 1.8V.
C
J
C
C max
C max
d
c
= T
= Case temperature of the package in
= Junction temperature of the die in
= Power dissipated in the die in Watts
= 17
J
= 120
= 101
- P
o
C/watt
d
(
o
o
c
C - 1.1 watts * (17
C
)
o
C. If the Ambient temperature is 70
o
C/watt)
o
C
o
C
resistor or write
www.national.com
o
C