September 1998
ML6633
High Speed Fiber Optic LED Driver
GENERAL DESCRIPTION
The ML6633 is a high speed fiber optic LED driver 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 driver’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 a vailable in an
8-pin SOIC package.
FEATURES
nData rates up to 200Mbps
nCurrent driven output for accur ate launch power
nProgrammable output current from 20mA to 82mA
nHigh Efficiency Output Stage
nLow EMI/RFI Noise
nECL inputs
nIndustrial temperature version a vailable
nMay be used with ML6622 quantizer
APPLICATIONS
nFDDI
nFast Ethernet, 100B ASE-FX
nATM (SONET), 155Mbps
nProprietary high-speed fiber optic data links
BLOCK DIAGRAM
1
+
BUFFER
–
+
DRIVER
–
IOUT
REF
RTSET
ECLP
ECLN
V
CC
GND
6
5
8
3
27
2
ML6633
PIN NAME DESCRIPTION
1 NC No Connect
2 ECLP P ositi v e ECL data input controls signal
to the LED
3 ECLN Negati v e ECL data input
4 NC No Connect
5 GND Negati ve po wer supply ground
PIN NAME DESCRIPTION
6 R TSET 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 driv e pin. Connect the
LED between this pin and VCC
8V
CC 5V power supply
PIN CONNECTION
PIN DESCRIPTION
ML6633
8-Pin SOIC (S08)
1
2
3
4
8
7
6
5
NC
ECLP
ECLN
NC
VCC
IOUT
RTSET
GND
TOP VIEW
3
ML6633
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
ICC Supply Current 40+IOUT mA
ILEDH LED Current Accuracy (IOUT) High C Suffix 70 75 82 mA
I Suffix 65 75 82 mA
ILEDL Low 0.1 mA
tRRise Time (IOUT) 2ns
t
F
Fall Time (IOUT) 2ns
t
PLH Propagation Delay (IOUT) Low to High 10 ns
tPHL High to Low 10 ns
tPWD Pulse Width Distortion (IOUT) 0.5 ns
IECL ECL Input Current 20 µA
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst-case test conditions.
ABSOLUTE MAXIMUM RATINGS
Absolute maximum ratings are those v alues beyond which
the device could be permanently damaged. Absolute
maximum ratings are stress r atings only and functional
device operation is not implied.
VCC ..................................................... GND –0.3V to 6V
Input Pin Voltages.................... GND –0.3V to VCC +0.3V
LED Output Current (IOUT)....................................82mA
Peak DC Output Current (IOUT) .............................82mA
Storage Temperature .............................. –65°C to +150ºC
Lead Temperature (Soldering 10 sec).......................260ºC
Thermal Resistance (θJA) ................................... 160ºC/W
OPERATING CONDITIONS
Temperature Range
ML6633CS .................................................... 0ºC to 70ºC
ML6633IS.................................................. –40ºC to 85ºC
4
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. T he 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. W ith 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 lev el, the ECLP pin can be
driven by a TTL or CMOS output. Figure 1b sho ws a cir cuit
implementing this technique. This circuit may degr ade
pulse width distortion and should be checked for
acceptable performance in this configuration.
Output current to the LED is set by connecting the
appropriate resistance from RTSET to ground. T he 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:
IHIGH V
RTSET
LED()=
2(1)
IHIGH VmA
LED()
.
==
2
261 75
Ω
Figure 1. Typical Applications
V
CC
I
OUT
RTSET
GND
5V
VIN+
VIN–
ECLP
ECLN
a) I
OUT
= 75mA
b) ECL-to-TTL Conversion
5V
5V
NC
NC
V
CC
I
OUT
RTSET
GND
5V
TTLIN ECLP
ECLN
5V
NC
NC
5
ML6633
6
ML6633
7
ML6633
8
ML6633
PHYSICAL DIMENSIONS inches (millimeters)
SEATING PLANE
0.148 - 0.158
(3.76 - 4.01)
PIN 1 ID 0.228 - 0.244
(5.79 - 6.20)
0.189 - 0.199
(4.80 - 5.06)
0.012 - 0.020
(0.30 - 0.51)
0.050 BSC
(1.27 BSC)
0.015 - 0.035
(0.38 - 0.89)
0.059 - 0.069
(1.49 - 1.75)
0.004 - 0.010
(0.10 - 0.26)
0.055 - 0.061
(1.40 - 1.55)
8
0.006 - 0.010
(0.15 - 0.26)
0º - 8º
1
0.017 - 0.027
(0.43 - 0.69)
(4 PLACES)
Package: S08
8-Pin SOIC
ORDERING INFORMATION
PART NUMBER TEMPERATURE RANGE PACKAGE
ML6633CS 0ºC to 70ºC 8-Pin SOIC (S08)
ML6633IS –40ºC to 85ºC 8-Pin SOIC (S08)
© 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 liab ility for use of any application
herein. The customer is urged to consult with appropriate legal counsel before deciding on a particular application.
9/18/98 Printed in U.S.A.
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San Jose, CA 95131
Tel: (408) 433-5200
Fax: (408) 432-0295
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