1
SY88702
Micrel
DESCRIPTION
s
Up to 622Mbps operation
s
Modulation current to 25mA
s
PECL output enable
s
Differential PECL inputs
s
Single 5V power supply
s
Available in a tiny 10-pin (3mm) MSOP
FEATURES
5V 622Mbps LASER DIODE
DRIVER WITH OUTPUT ENABLE
SY88702
APPLICATIONS
s
622Mbps SONET
Rev.: A
Amendment: /0
Issue Date:
March 2003
The SY88702 is a high-speed current switch for driving
a semiconductor laser diode in optical transmission
applications. The modulation current (I
OUT
) is controlled
by the current (I
RSET
) through the external resistor R
SET
.
The output OUT is HIGH and no current flows through
OUT when output enable is HIGH.
The device incorporates complementary open collector
outputs with 25mA maximum current driving capability.
The external resistor R
EXT
must be placed between
/OUT and V
CC
to dissipate the worst case power. R
SER
is recommended to compensate for laser diode matching
issues.
The SY88702 utilizes the high performance bipolar
ASSETTM technology.
ASSET is a trademark of Micrel, Inc.
FUNCTIONAL BLOCK DIAGRAM
R
EXT
V
CC
/EN
/DIN
DIN
Internal
Logic
V
CC
V
EE
R
SET
R
SET
V
REF
40X
R
SER
I
MOD
/OUT
GND
to Laser Diode
OUT
2
SY88702
Micrel
PACKAGE/ORDERING INFORMATION
Ordering Information
Package
Operating
Package
Part Number
Type
Range
Marking
SY88702KC
K10-1
Commercial
702
SY88702KCTR*
K10-1
Commercial
702
SY88702KI
K10-1
Industrial
702
SY88702KITR*
K10-1
Industrial
702
*Tape and Reel
Pin Number
Pin Name
Pin Function
1
/EN
100k PECL compatible input with 75k
pull-down resistor. Modulation current goes to zero
when deasserted high.
2, 3
DIN, /DIN
Differential 100k PECL compatible input with 75k
pull-down resistors.
4
VREF
Voltage reference for use with R
SET
.
5
RSET
An external resistor connected from here to V
REF
sets the reference current for I
OUT
.
6, 7
GND
Device ground.
9, 8
OUT, /OUT
Differential open collector current outputs.
10
VCC
Positive power supply.
PIN DESCRIPTION
RSET
GND
6
5
1
/EN
DIN
/DIN
VREF
10 VCC
OUT
/OUT
GND
9
8
7
2
3
4
10-Pin MSOP
(K10-1)
D
/D
/EN
OUT
(2)
/OUT
L
H
L
H
L
H
L
L
L
H
X
X
H
H
L
Note 1. L = LOW, H = HIGH, X = don't care.
Note 2. H = I
OUT
= 0mA.
TRUTH TABLE
(1)
3
SY88702
Micrel
Absolute Maximum Ratings
(Note 1)
Power Supply Voltage (V
CC
) ............................ 0V to +7.0V
Input Voltage (V
IN
) .............................................. 0V to V
CC
Output Current (I
OUT
) ................................................. 25mA
Power Dissipation (P
D
) ........................................... 250mW
Storage Temperature Range (T
S
) ............ 55
C to +125
C
Operating Ratings
(Notes 2,3,4)
Supply Voltage (V
CC
) .................................. +4.5V to +5.5V
Ambient Temperature (T
A
), Note 5 ............ 40
C to +85
C
Junction Temperature (T
J
), Note 5 ............ 40
C to 100
C
Resistor to Dissipate Power (R
EXT
) .................. 10
to 50
Laser Diode Serial Resistor (R
SER
) .................... 0
to 50
Resistor to Adjust Current (R
SET
) .......... 1500
to 50,000
Package Thermal Resistance
MSOP
(
JA
) Still-Air ...................................................... 113
C/W
(
JB
) Still-Air ........................................................ 74
C/W
GND = 0V; V
CC
= 5V
10%; T
A
= 40
C to +85
C
Symbol
Parameter
Condition
Min
Typ
Max
Units
V
IH
Input HIGH Voltage
V
CC
1.165
V
CC
0.880
V
(D
IN
, /D
IN
, /EN)
V
IL
Input LOW Voltage
V
CC
1.810
V
CC
1.475
V
(D
IN
, /D
IN
, /EN)
V
REF
Reference Voltage
3.00
V
I
IL
Input LOW Current
V
IN
= V
IL
(min)
0.5
A
(D
IN
, /D
IN
, /EN)
I
IH
Input HIGH Current
100
A
(D
IN
, /D
IN
, /EN)
I
CC
Supply Current
I
MOD
= 25mA
16
25
mA
I
OUT_OFF
Output LOW Current
500
A
(/EN = HIGH)
I
OUT
Modulation Current
5
15
25
mA
A
RSET
I
OUT
/I
RSET
30
38
44
--
V
OUT
Voltage at OUT, /OUT
V
CC
2.3
V
CC
V
C
OUT
Capacitance on OUT, /OUT
2.5
pF
Note 1.
Specification for packaged product only.
DC ELECTRICAL CHARACTERISTICS
(Note 1)
Note 1.
Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. This is a stress rating only and functional operation
is not implied at conditions other than those detailed in the operational sections of this data sheet. Exposure to ABSOLUTE MAXIMUM
RATlNG conditions for extended periods may affect device reliability.
Note 2.
The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
Note 3.
The device is guaranteed to meet the DC specifications, shown in the table above, after thermal equilibrium has been established. The device
is tested in a socket such that transverse airflow of
500lfpm is maintained.
Note 4.
The voltage drop across R
EXT
and R
SER
plus Laser Diode must not be greater than 2.3V.
Note 5.
Commercial devices are guaranteed from 0
C to +85
C ambient temperature.
4
SY88702
Micrel
GND = 0V; V
CC
= 5V
10%; T
A
= 40
C to +85
C
Symbol
Parameter
Condition
Min
Typ
Max
Units
t
PHL,
t
PLH
D
Propagation Delay
I
OUT
= 10mA
1000
ps
D
IN
OUT
t
PHL,
t
PLH
EN
Propagation Delay
I
OUT
= 10mA
1000
ps
/EN OUT
t
r
Rise/Fall Time
400
ps
t
f
(20% to 80%)
I
OR
Output Current Ringing
I
OUT
= 5 to 25mA
10
%
Note 1.
Specification for packaged product only.
Note 1.
R
EXT
= R
SER
= 50
1%; R
SER
connected directly to V
CC
.
AC ELECTRICAL CHARACTERISTICS
(Note 1, 2)
TYPICAL OPERATING CHARACTERISTICS
10
20
25
30
I
OUT
(mA)
0
0
15
5
4
6
8
10
2
R
SET
(9)
12
I
OUT
vs. R
SET
V
CC
= 5V
T
A
= 55C
5
SY88702
Micrel
10 LEAD MSOP (K10-1)
Rev. 00
MICREL, INC.
1849 FORTUNE DRIVE
SAN JOSE, CA 95131
USA
TEL
+ 1 (408) 944-0800
FAX
+ 1 (408) 944-0970
WEB
http://www.micrel.com
The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's
use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser's own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
2003 Micrel, Incorporated.
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