ml6652 Sirenza Microdevices, ml6652 Datasheet - Page 11

• Manufacturer Part Number: ml6652
• Description: 10/100mbps Ethernet Fiber And Copper Media Converter With Auto-negotiation
• Manufacturer: Sirenza Microdevices

11
Pin No. Signal Name
BACKUP LINK FUNCTION
LED STATUS
PIN DESCRIPTIONS (continued)
40
41
42
43
BCKPLINK
FOINSPD
TPINSPD
TPANDT
I / O
I/O
O
O
O
January 2004
Description
PECL/LVPECL Compatible Interface Mode:
This input pin is connected to the Signal Detect (SD) output of a fiber optic
PMD. The voltage level at this pin is compared to the voltage level at pin
SDTH to determine the logic value. If it is lower than the input at FOINP/
FOINN is rejected. If it is higher than the input at FOINP/FOINN is passed to
the internal circuits.
INPUT MODE:
At power up, pin 40 (BCKPLINK) is read and the BCKPDIS register <28.1> is set
appropriately. A high (VCC) at power up causes Register 28, Bit 1 (BCKPDIS)
to be set high (1) disabling the Back-up link function. BCKPDIS can
subsequently be over written by the management interface at any time.
Note: This pin is typically read a few microseconds after power-up, if it is tied
to supplies that do not track the ML6652 power, improper results may occur.
For BCKPLINK, use VCCD (pin 19) as the pull up point, do not add decoupling
capacitors to Pin 40 (without thoroughly understanding your PCB layout power
up dynamics the safest course is to make short connections and do not add
decoupling capacitors to this pin).
OUTPUT MODE:
After power-up, BCKPLINK is used as an output. It is Active high to enable a
secondary fiber link via a second ML6652 device (see Functional Description,
Backup Link Mode in this data sheet for details).
Use this function in forced 100Mbps mode, non loopback only
This output goes high to indicate that a 100Mbps signal is present at the TPINP/
TPINN interface, and it goes low to indicate that a 10Mbps signal is present at
the TPINP/TPINN interface. The signal can be idle or packets. This pin is set to
high impedance otherwise.
This output goes high to indicate that a 100Mbps signal is present at the
FOINP/FOINN interface, and it goes low to indicate that a 10Mbps signal is
present at the FOINP/FOINN interface. The signal can be idle or packets. This
pin is set to high impedance otherwise.
When TPINSPD is in the high impedance state, no 10 or 100Mbps signal at
TPINP/TPINN, the TPANDT LED pulls low while receiving Auto-Negotiation
signal at the TPINP/TPINN interface. When TPINSPD is not in the high
impedance state, the TPANDT pin pulls low to indicate that a data packet is
being detected at the TPINP/TPINN interface. When a data packet is indicated,
the pulse width at TPANDT is stretched to a minimum of 1.3 to 2.7ms to
improve visibility. In any other case this pin is in high impedance state.
Final Datasheet
DS6652-F-02
ML6652