SY88782L
3.3V, 1.25Gbps High Current, Low Power Laser
Driver for Datacom Telecom Applications
Micro
LeadFrame is a trademark of Amkor Technology, Inc.
February 2005
M9999-021005
hbwhelp@micrel.com
or (408) 955-1690
General Description
The SY88782L is a single supply 3.3V low power
consumption, small form factor, driver for
telecom/datacom applications using FP/DFB lasers
at data rates up to 1.25Gbps. The driver can deliver
modulation current up to 90mA, and the high
compliance voltage it offers makes the part suitable
for high-current operation (with the laser AC- or DC-
coupled to it.) This device is intended to be used
with Micrel MIC3000/1 Optical Transceiver
Management IC which allows for modulation and
bias currents control and monitoring, automatic
power Control, and temperature compensation.
All support documentation can be found on Micrel's
web site at:
www.micrel.com
.
Features
2.3V minimum laser compliance voltage
44mA power supply current typical
Operation up to 1.25Gbps
Modulation current up to 90mA
Designed for use with the MIC3000/1
Small form factor 3mm x 3mm MLFTM package
Applications
Multi-rate LAN, MAN applications up to 1.25Gbps:
Ethernet, SONET OC3/12/24 and SDH STM1/4/8
SFF, SFP Modules
Markets
Telecom, Datacom
________________________________________________________________
Typical Application
Laser DC-Coupled to the Driver
Laser AC-Coupled to the Driver
Micrel, Inc.
SY88782L
February 2005
3
M9999-021005
hbwhelp@micrel.com
or (408) 955-1690
Pin Description
Pin Name
Pin Number
Pin Function
1, 4, 7, 8, 13
GND
Ground. Ground and exposed pad must be connected to the plane of the most
negative potential.
2 DIN+
Non-inverting input data. Internally terminated with 50
to a reference voltage.
3 DIN
Inverting input data. Internally terminated with 50
to a reference voltage.
5, 6
VCC
Supply Voltage. Bypass with a 0.1F//0.01F low ESR capacitor as close to VCC
pin as possible.
9, 10
MOD
Inverted modulation current output. Outputs modulation current when input data is
negative.
11, 12
MOD+
Non-inverted modulation current output. Outputs modulation current when input
data is positive.
14
VREF
Reference Voltage. Install a 0.1F capacitor between VREF and VCC.
15 IM_SET
Modulation current setting and control. The voltage applied to this pin will set the
modulation current. To be connected to the MIC3000/1 pin 24 (VMOD+). Input
impedance 25K
.
16 /EN
A low level signal on this pin will enable the output stage of the driver. Internally
pulled down with 75K
.
Truth Table
DIN+ DIN- /EN
MOD+
(1)
MOD- Laser
Output
(2)
L H L
H
L L
H L L L
H H
X X H
H
L L
Notes:
1. I
MOD
= 0 when MOD+ = H.
2. Assuming that the laser is tied to MOD+.
Micrel, Inc.
SY88782L
February 2005
4
M9999-021005
hbwhelp@micrel.com
or (408) 955-1690
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) ...........................0.5V to +4.0V
CML Input Voltage (V
IN
).......... V
CC
1.2V to V
CC
+0.5V
TTL Control Input Voltage (V
IN
) ...................0V to V
CC
Lead Temperature (soldering, 20sec.) ...........+260C
Storage Temperature (T
s
)............... 65C to +150C
Operating Ratings
(2)
Supply Voltage (V
CC
)...........................+3.0V to +3.6V
Ambient Temperature (T
A
)................ 40C to +85C
Package Thermal Resistance
(3)
MLFTM
(
JA
) Still-air ............................................. 60C/W
(
JB
) ......................................................... 33C/W
DC Electrical Characteristics
T
A
= 40C to +85C and V
CC
= +3.0V to +3.6V, unless otherwise noted. Typical values are V
CC
= +3.3V, T
A
= 25C,
I
MOD
= 60mA.
Symbol Parameter
Condition
Min
Typ
Max
Units
I
CC
Power Supply Current
Modulation currents excluded
44
60
(4)
mA
V
MOD_MIN
Minimum Voltage Required at the
Driver Output (headroom) for
Proper Operation
0.7
V
R
IN(DATA)
Input Resistance (DIN+, DIN-)
45
50
55
V
ID
Differential Input Voltage Swing
200
2400
mV
pp
/EN Low
0.8
V
/EN High
2
V
R
IN (IMOD_SET)
I
M_SET
Input Resistance
25
k
V
IM_SET
Voltage Range on I
M_SET
Pin
I
MOD
range 10mA to 90mA
1.2
V
AC Electrical Characteristics
T
A
= 40C to +85C and V
CC
= +3.0V to +3.6V, unless otherwise noted. Typical values are V
CC
= +3.3V, T
A
= 25C,
I
MOD
= 60mA.
Symbol Parameter
Condition
Min
Typ
Max
Units
Data
Rate
NRZ
0.05 1.25
Gbps
I
MOD
Modulation
Current
(5)
AC-coupled
10
90
mA
DC-coupled
10
70
(6)
mA
I
MOD_OFF
Modulation OFF Current
Current at MOD+ when the
device is disabled
750
A
t
r
Output Current Rise Time
20% to 80%, I
MOD
= 60mA
80
ps
t
f
Output Current Fall Time
20% to 80%, I
MOD
= 60mA
80
ps
Total Jitter
@1.25Gbps data rate
20
ps
PP
Pulse-Width Distortion
20
ps
Notes:
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 ratings
conditions for extended periods may affect device reliability.
2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
3. Package Thermal Resistance assumes exposed pad is soldered (or equivalent) to the devices most negative potential on the PCB.
JB
uses a 4-layer and
JA
in still air unless otherwise stated.
4. I
CC
= 60mA for worst-case conditions with I
MOD
= 90mA, T
A
= +85C, V
CC
= 3.6V.
5. Load = 15.
6. Assuming
V
CC
= 3.0V, Laser bandgap voltage = 1V, laser package inductance = 1nH, laser equivalent series resistor = 5, and damping
resistor = 10.
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