Micro Linear Corporation ML4667CQ Datasheet

March 1997

ML4667

Low Power 10BASE-FL Transceiver

GENERAL DESCRIPTION

The ML4667 is a low power high output current pin
compatible version of the industry standard ML4662. The
ML4667 10Base-FL transceiver combined with either the
ML4622 or ML4624 fiber optic quantizer provide all
functionality required to implement both an internal and
external IEEE 802.3 10Base-FL MAU interface that allows
it to be directly connected to industry standard
manchester encoder/decoder chips or and AUI cable.

The ML4667 provides a highly integrated solution that
requires a minimal number of external components. The
ML4667 is compliant to the IEEE 802.3 10Base-FL
standard. The transmitter offers a 100mA maximum
current driven output that directly drives a fiber optic LED
transmitter. Jabber, a 1MHz idle signal, and SQE Test are
fully integrated onto the chip.

The receiver accepts and ECL level input from the
ML4622 or ML4624 fiber optic quantizer. The 1MHz idle
signal is removed and the AUI output is activated when
the receive squelch criteria is exceeded. A Link Monitor
function is also provided for low light detection.

BLOCK DIAGRAM

FEATURES

■ Combined with the ML4622 or ML4624, offers a

complete implementation of an 10Base-FL Medium
Attachment Unit (MAU)

■ Pin compatible with the ML4662 Transceiver

■ Incorporates an AU interface for use in an external

MAU or an internal MAU

■ 100mA max LED output current drive

■ Single +5 volt supply ±10%

■ No crystal or clock required

■ On-chip Jabber, 1MHz idle, and SQE Test with enable/

disable option

■ Five network status LED outputs

+5V

SQEN/JABD V

Tx+

10

Tx–

11

COL+

2

COL–

3

Rx+

6

Rx–

7

21 8 13 23 1 28 16 15 24

AUI

RECEIVER

Tx

SQUELCH

AUI

DRIVER

AUI

DRIVER

V

CC

(+5V)GND

1MHz

IDLE

SIGNAL

SQE

10MHz GATED

OSCILLATOR

LOOPBACK

MUX

Tx

Rx

Tx

CC

(+5V)

FIBER OPTIC

LED DRIVER

JABBER

DRIVERS

RTSET NC/PEAK

RECEIVE SQUELCH

FREQUENCY

RECEIVER

LED

19174 12

LINE

TxOUT

18

LMON

IN

22

RxIN+

26

RxIN–

25

27

LMONXMTRCVJABCLSNLBDISRRSET

BIAS

+5V

1

ML4667

PIN CONNECTION

NC/GND

Rx+

Rx–

V

CC

V

CC

Tx+

Tx–

ML4667

28-Pin PLCC (Q28)

SQEN/JABD

COL–

COL+

CLSN

JAB

4 3 2 1 28 27 26

5

6

7

8

9

10

11

12 13 14 15 16 17 18

BIAS

RxIN+

25

24

23

22

21

20

19

RxIN–

LMON

LBDIS

LMON

IN

GND

GND

NC/PEAK

RTSET

RRSET

NC

XMT

RCV

Tx

CC

V

TxOUT

2

PIN DESCRIPTION

ML4667

PIN NAME FUNCTION

1 CLSN Indicates that a collision is taking

place. Active low LED driver, open
collector. Event is extended with
internal timer for visibility.

2 COL+ Gated 10MHz oscillation used to
3 COL– indicate a collision, SQE test, or

jabber. Balanced differential line
driver outputs that meet AUI
specifications.

4 SQEN/JABD SQE Test Enable, Jabber Disable.

When tied low, SQE test is disabled,
when tied high SQE test is enabled.
When tied to BIAS both SQE test and
Jabber are disabled.

5 NC/GND No connection. This pin may be

grounded.

6 Rx+ Manchester encoded receive data
7 Rx– output to the local device. Balanced

differential line driver outputs that
meet AUI specifications.

8VCC+5 volt power input.
9V

10 Tx+ Balanced differential line receiver
11 Tx– inputs that meet AUI specifications.

12 RTSET Sets the current driven output of the

13 RRSET A 1% 61.9kΩ resistor tied from this

14 NC No Connection

15 XMT Indicates that transmission is taking

CC

These inputs may be transformer, AC
or DC coupled. When transformer or
AC coupled, the BIAS pin is used to
set the common mode voltage

transmitter.

pin to VCC sets the biasing currents
for internal nodes.

place. Active low LED driver, open
collector. Event is extended with
internal timer for visibility.

PIN NAME FUNCTION

19 NC/PEAK Normally this pin can be left

floating. (tying it to GND or VCC is
OK too.) Some fiber optic LEDs may
need an additional peaking circuit
to speed-up the rise and fall times.
For this case, tie pin 19 (NC/PEAK)
to pin 18 (TxOUT). When using the
HP HFBR 1414, let pin 19 float.
Using the peaking circuit may
deteriorate optical overshoot and
undershoot.

20 GND Ground reference.

21 GND Ground reference.

22 LMON

23 LBDIS Loopback Disable. When this pin is

24 LMON Link Monitor LED status output.

25 RxIN– Fiber optic receive pair. This ECL
26 RXIN+ level signal is received from the

IN

Link Monitor Input from the
ML4622 or ML4624. This input
must be low (active) for the receiver
to unsquelch.

tied to VCC, the AUI transmit pair
data is not looped back to the AUI
receive pair, and collision is
disabled. When this pin is tied to
GND (normal operation), the AUI
transmit pair data is looped back to
the AUI receiver pair.

This pin is pulled low when

LMON

transitions on RxIN± indicating and

idle signal or active data. If either

LMONIN goes high or transitions

cease on RxIN±, LMON will go

high, Active low LED driver, open
collector.

ML6422 or ML4624 fiber optic
quantizer. When this signal exceeds
the receive squelch requirements,
and the LMONIN input is low, the
receive data is buffered and sent to
the AUI receive outputs.

is low and there are

IN

16 RCV Indicates that the transceiver is

receiving a frame from the optical
input. Active low LED driver, open
collector. Event is extended with
internal timer for visibility.

17 VCCTx +5 volt supply for LED driver.

18 TxOUT Fiber optic LED driver output.

27 BIAS BIAS output voltage for the AUI

Tx+, Tx– inputs when they are AC
coupled.

28 JAB Jabber network status LED. When in

the Jabber state, this pin will be low
and the transmitter will be disabled.
In the Jabber “OK” state this pin will
be high. Open collector TTL output.

3

ML4667

ABSOLUTE MAXIMUM RATINGS

Output Current

TxOUT .............................................................. 120mA

Absolute maximum ratings are those values beyond which
the device could be permanently damaged. Absolute
maximum ratings are stress ratings only and functional
device operation is not implied.

Power Supply Voltage Range

VCC..................................................... GND –0.3 to 6V

Junction Temperature .............................................. 150°C

Storage Temperature Range .................... –65°C to +150°C

Lead Temperature (Soldering) .................................. 260°C

Thermal Resistance (θJA)...................................... 68°C /W

OPERATING CONDITIONS

Input Voltage Range

Digital Inputs (SQEN, LMONIN, LBDIS)

.................................................. GND –0.3 to V

Tx+, Tx–, RxIN+, RxIN– ............ GND –0.3 to V

CC
CC

Input Current

RRSET, RTSET, JAB, CLSN, XMT, RCV, LMON ...... 60mA

+0.3
+0.3

Supply Voltage (V

) ........................................... 5V ± 5%

CC

LED on Current ....................................................... 10mA

RRSET .......................................................... 61.9kΩ ± 1%

RTSET ............................................................. 162Ω ± 1%

ELECTRICAL CHARACTERISTICS

Unless otherwise specified, TA = Operating Temperature Range, V

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

I

CC

V

I

OUT

V

OL

SQ

Power Supply Current ICC:V
While Transmitting

LED Drivers IOL = 10mA (Note 3) 0.8 V

Transmit Peak Output Current RTSET = 162Ω, 475260mA

Transmit Squelch Voltage Level –300 –250 –200 mV
(Tx+, Tx–)

= 5V, RTSET = 162Ω (Note 2) 120 mA

CC

V

= V

CC

Tx = 5V ±5% (Note 4)

CC

= 5V ± 10% (Note 1)

CC

V

V

V

V

V

V

V

INCM

DO

CM

DOO

BIAS

SQE

LBTH

Common mode Input Voltage 2 VCC – 0.5 V

(Tx±, RxIN±)
Differential Output Voltage ±550 ±1200 mV

(Rx±, COL±)

Common Mode 4.0 V

Output Voltage (Rx±, COL±)
Differential Output ±40 mV

Voltage Imbalance (Rx±, COL±)

BIAS Voltage 3.2 V

SQE/JABD SQE Test Disable 0.3 V

Both Disabled 1.5 V
Both Enabled VCC – 0.5

LBDIS Threshold Disabled VCC – 0.10 V

Enabled 1 V

CC

– 2

4