July 2000
ML4664*/ML4669*
10BASE-FL to 10BASE-T Converter
GENERAL DESCRIPTION
The fully pin-compatible ML4664/ML4669 pair provide
conversion from 10BASE-T copper media to 10BASE-FL
fiber media in a single chip. They are compliant with
Ethernet IEEE 802.3 10BASE-T and 10BASE-FL standards.
The ML4664/69 uses a single 5V supply, and requires no
crystal or clock.
Their 10BASE-FL transmitter offers a current drive output
that directly drives a fiber optic LED transmitter. Their
receiver offers a highly stable fiber optic data quantizer
capable of accepting input signals as low as 2mV
P-P
with
a 55dB dynamic range.
The 10BASE-T portion of the pair contains current driven
transmitter outputs that offer superior performance
because their switching is highly symmetric, resulting in
lowered RFI noise and jitter. By changing one external
resistor the pair easily interfaces to 100W unshielded
twisted pair, 150W shielded twisted pair, or a range of
other characteristic impedances.
The ML4664 does not pass along disconnect information,
while the ML4669 does. A loss of light at the optical
inputs does not stop link pulses from being sent at the
twisted pair transmitter in the ML4664, but in the
ML4669 the link pulses stop. Also, a loss of link at the
twisted pair inputs will not stop the optical transmitter
from sending idle in the ML4664, but the ML4669 stops
sending idle.
FEATURES
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Full duplex operation
Five network status LED outputs
Industrial temperature option
10BASE-FL FEATURES:
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Highly stable data quantizer with 55dB input dynamic
range
Input sensitivity as low as 2mV
P-P
Up to 100mA maximum current driven fiber optic LED
output for accurate launch power (PLCC package)
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10BASE-T FEATURES:
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Current driven output for low RFI noise and low jitter
Drives 100W unshielded or 150W shielded twisted pair
Polarity detect status pin capable of driving an LED
Automatic polarity correction
On-chip link test with enable/disable option
* Some Packages Are Obsolete
BLOCK DIAGRAM
LTF
LINK PULSE
CHECK
TPLED
POLDIS
IDLE
GENERATOR
RRSET
RTSETOP
TPIN
2
RX SQUELCH
TP
OP
TX
OPOUT
OPVCC
POLARITY
CORRECT
LINK PULSE
GENERATOR
RX SQUELCH
TP
TPOUT
2
RTSETTP
TP
TX
TxCAP0
TxCAP1
LMON
(LOW LIGHT)
THRESHOLD
GENERATOR
QUANTIZER
OPLED
VDC
CTIMER
2
OPIN
1
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
