ML4664/ML4669
PIN DESCRIPTION
(Continued)
PIN
NAME
FUNCTION
PIN
NAME
FUNCTION
17(15)
LMON
Link Monitor “Low Light” LED status
output. Pulled low when voltage on
the OPINP, OPINN inputs exceed min
threshold set by V
THADJ
, and there are
transitions on OPINP, OPINN
indicating an idle signal or active
data. If the voltage on OPINP, OPINN
inputs falls below the minimum
threshold or transitions cease on
OPINP, OPINN, LMON will go high.
Active low LED driver, open collector.
In the low light state, optical and
twisted pair transmitters are disabled
from sending data. The optical
transmitter of the ML4664 does send
an idle signal, and link pulses are sent
at the twisted pair transmitter. For the
ML4669, the twisted pair transmitter
will not send link pulses, the optical
transmitter may send an idle signal,
depending on inputs. See Table 1.
22(21) V
REF
23(22) V
THADJ
24(23) AGND
25(24) OPINN
A 2.5V reference with respect to GND
This input pin sets the link monitor
threshold
Analog Filtered Ground
This input pin should be capacitively
coupled to filtered AV
CC
. The input
resistance is approximately 1.3kW.
This input pin should be capacitively
coupled to the input source. The input
resistance is approximately 1.3kW.
Analog Filtered 5V
Indicates reception is taking place on
the OPINP, OPINN pair. Active low
LED driver, open collector. It is
extended 16ms for usability. This pin
may be grounded to disable the
twisted pair outputs. If this pin is not
used as an LED driver, and is not
grounded, a 2kW, 5% resistor should
be connected between this pin and
V
CC
.
26(25) OPINP
27(26) AV
CC
28(28) OPLED
18(16) OPVCC
19(17) OPOUT
21(20) V
DC
5V supply for fiber optic
LED driver
Fiber optic LED driver output
An external capacitor on this pin
integrates an error signal which nulls
the offset of the input amplifier. If the
DC feedback loop is not being used,
this pin should be connected to V
REF
.
4
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
