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September 1998
ML6633*
High Speed Fiber Optic LED Driver
GENERAL DESCRIPTION
The ML6633 is a high speed fiber optic LED dri v er suited
for networking applications up to 200 Mbps. The part is
capable of driving up to 82mA of current through a fiber
optic LED from an ECL level input signal. Its efficient
output stage provides a high current that can be
programmed for accurate absolute output level which
insures precise launch power.
The LED driv er’s output stage provides a fast well
matched rise and fall time through a unique differential
output stage.
The ML6633 high speed fiber optic LED driver is
implemented in BiCMOS process and is available in an
8-pin SOIC package.
FEATURES
n Data rates up to 200Mbps
n Current driven output for accurate launch po wer
n Programmable output current from 20mA to 82mA
n High Efficiency Output Stage
n Low EMI/RFI Noise
n ECL inputs
n Industrial temperature version av ailable
n May be used with ML6622 quantizer
APPLICATIONS
n FDDI
n Fast Ethernet, 100BASE-FX
n A TM (SONET), 155Mbps
n Proprietary high-speed fiber optic data links
BLOCK DIAGRAM *Some Packages Are Obsolete
IOUT
7
RTSET
6
2
3
8
5
ECLP
ECLN
V
CC
GND
+
BUFFER
–
REF
+
DRIVER
–
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ML6633
PIN CONNECTION
PIN DESCRIPTION
ML6633
8-Pin SOIC (S08)
NC
ECLP
ECLN
NC
1
2
3
4
TOP VIEW
8
V
CC
7
IOUT
6
RTSET
5
GND
PIN NAME DESCRIPTION
1 NC No Connect
2 ECLP Positiv e ECL data input controls signal
to the LED
3 ECLN Negative ECL data input
4 NC No Connect
5 GND Negative power supply ground
PIN NAME DESCRIPTION
6 RTSET Output current programming pin.
Connect a resistor of value 2/I
LED
from
this pin to ground to set the high LED
output current
7 IOUT Fiber optic LED drive pin. Connect the
8V
CC
LED between this pin and V
5V power supply
CC
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ABSOLUTE MAXIMUM RATINGS
ML6633
Absolute maximum ratings are those values beyond which
the device could be permanently damaged. Absolute
maximum ratings are stress ratings only and functional
Storage Temperature.............................. –65°C to +150ºC
Lead Temperature (Soldering 10 sec).......................260ºC
Thermal Resistance (θJA) ................................... 160ºC/W
device operation is not implied.
VCC..................................................... GND –0.3V to 6V
OPERATING CONDITIONS
Input Pin Voltages .................... GND –0.3V to VCC +0.3V
LED Output Current (IOUT)....................................82mA
Peak DC Output Current (IOUT).............................82mA
Temperature Range
ML6633CS .................................................... 0ºC to 70ºC
ML6633IS.................................................. –40ºC to 85ºC
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, VCC = 5V ± 5%, RTSET = 26.1Ω ± 1%, TA = Operating Temperature Range, (Note 1)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
CC
I
LEDH
I
LEDL
t
t
t
PLH
t
PHL
t
PWD
I
ECL
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst-case test conditions.
Supply Current 40+I
LED Current Accuracy (IOUT) High C Suffix 70 7 5 82 mA
I Suffix 65 7 5 82 mA
Low 0.1 mA
Rise Time (IOUT) 2ns
R
Fall Time (IOUT) 2ns
F
Propagation Delay (IOUT) Low to High 10 ns
High to Low 10 ns
Pulse Width Distortion (IOUT) 0.5 ns
ECL Input Current 20 µA
OUT
mA
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ML6633
FUNCTIONAL DESCRIPTION
The ML6633 accepts ECL input signals and generates a
high speed, high accuracy output current which is
independent of supply voltage variations. The output
current is programmable up to 82mA.
The ECL input stage is a standard NPN differential pair
with a common mode range of between 1V and 4.5V with
a +5V supply. With this common mode r ange it is possible
to convert the ECL inputs into TTL. If the ECLN input is
biased up to the TTL switching level, the ECLP pin can be
driven by a TTL or CMOS output. Figure 1b shows a circuit
implementing this technique. This circuit ma y degr ade
pulse width distortion and should be checked for
acceptable performance in this configuration.
NC
VIN+
ECLP
Output current to the LED is set by connecting the
appropriate resistance from RTSET to ground. The high
level output voltage at RTSET will be 2.0V. The current in
the external resistor will be equal to the current through
the LED. The output current with RTSET set to 26.1Wwill
be:
V
IHIGH
()=
LED
IHIGH
()
LED
5V
V
CC
I
OUT
2
RTSET
V
2
==
.
26175Ω
5V
mA
(1)
5V
VIN–
NC
NC
TTLIN
NC
ECLN
a) I
ECLP
ECLN
b) ECL-to-TTL Conversion
OUT
RTSET
GND
= 75mA
V
CC
I
OUT
RTSET
GND
5V
5V
Figure 1. Typical Applications
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ML6633
PHYSICAL DIMENSIONS inches (millimeters)
0.189 - 0.199
(4.80 - 5.06)
8
Package: S08
8-Pin SOIC
0.017 - 0.027
(0.43 - 0.69)
(4 PLACES)
0.055 - 0.061
(1.40 - 1.55)
PIN 1 ID
1
0.050 BSC
(1.27 BSC)
0.012 - 0.020
(0.30 - 0.51)
SEATING PLANE
0.148 - 0.158
(3.76 - 4.01)
0.059 - 0.069
(1.49 - 1.75)
0.228 - 0.244
(5.79 - 6.20)
0.004 - 0.010
(0.10 - 0.26)
0º - 8º
0.015 - 0.035
(0.38 - 0.89)
0.006 - 0.010
(0.15 - 0.26)
ORDERING INFORMATION
PART NUMBER TEMPERATURE RANGE PACKAGE
ML6633CS 0ºC to 70ºC 8-Pin SOIC (S08)
ML6633IS–40ºC to 85ºC8-Pin SOIC (S08) (Obolsete)
© Micro Linear 1998. is a registered trademark of Micro Linear Corporation. All other trademarks are the property of their respective owners.
Products described herein may be covered by one or more of the following U.S. patents: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483;
5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470; 5,565,761; 5,592,128; 5,594,376; 5,652,479; 5,661,427; 5,663,874; 5,672,959;
5,689,167; 5,714,897; 5,717,798; 5,742,151; 5,747,977; 5,754,012; 5,757,174; 5,767,653; 5,777,514. Japan: 2,598,946; 2,619,299; 2,704,176. Other
patents are pending.
Micro Linear reserves the right to make changes to any product herein to improve reliability, function or design. Micro Linear does not assume any
liability arising out of the application or use of any product described herein, neither does it convey any license under its patent right nor the rights of
others. The circuits contained in this data sheet are offered as possible applications only. Micro Linear makes no warranties or representations as to
whether the illustrated circuits infringe any intellectual property rights of others, and will accept no responsibility or liability for use of any application
herein. The customer is urged to consult with appropriate legal counsel before deciding on a particular application.
5
2092 Concourse Drive
San Jose, CA 95131
T el: (408) 433-5200
Fax: (408) 432-0295
www .microlinear.com
DS6633-01
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