SY88024L
11.3Gbps VCSEL DRIVER
General Description
The SY88024L is a single 3.3V supply, small form factor
VCSEL driver for datacom applications at data rates up to
11.3Gbps. The driver can deliver modulation current up to
20mA and a bias current up to 20mA
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
.
Features
•
•
•
•
•
Operates from a single 3.3V supply
Operation up to 11.3Gbps
Modulation current up to 20mA
Bias current up to 20mA
Small form factor 3mm x 3mm QFN package
Applications
• Multi-rate LAN up to 11.3Gbps: 8xFC, 10G GbE.
• SFP+, XFP, XPAK, XENPAK, X2, MSA 300 optical
modules
__________________________________________________________________________________________
Typical Application
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
October 2009
M9999-102809-A
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Micrel, Inc.
SY88024L
Ordering Information(1)
Part Number
SY88024LMG
(2)
SY88024LMGTR
Voltage
Temperature Range
Package
Lead Finish
3.3V
–40° to +85°C
QFN-16
NiPdAu Pb-Free
3.3V
–40° to +85°C
QFN-16
NiPdAu Pb-Free
Notes:
1. Contact factory for die availability. Dice are guaranteed at TA = +25°C, DC Electricals only.
2. Tape and Reel.
Pin Configuration
16-Pin QFN
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SY88024L
Pin Description
Pin Number
Pin Name
Pin Function
1, 4, 9, 12
VCC
Supply Voltage. Bypass with a 0.1µF//0.01µF low ESR capacitor as close to the
VCC pins as possible.
8, 14
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 Ω to VCC.
3
DIN–
Inverting input data. Internally terminated with 50 Ω to VCC.
5
MODSET
Modulation current setting and control. Apply a voltage within the range 0V to1.2V
to this pin to set the modulation current. Input impedance 25k Ω.
6
/EN
Active Low TTL. Internal 75kΩ pull down to GND. The driver is enabled when this
pin is unconnected or /EN is asserted low and disabled when /EN asserted high.
7
EQSET
Install a resistor from this pin to GND to set the desired equalization level. 0 Ω will
provide maximum equalization and 2kΩ or higher will provide negligible
equalization. Leave open if no equalization is needed.
10
MOD–
Inverted modulation current output. Provides modulation current when input data is
negative.
11
MOD+
Non-inverted modulation current output. Provides modulation current when input
data is positive.
13
BIAS
15
BIASMON
Bias Current Monitor. Install an external resistor from this pin to GND to convert
the output current to a voltage proportional to the bias current
16
BIASSET
Bias current setting and control. Apply a voltage within the range 0V to 1.2V to this
pin to set the bias current. Input impedance 25kΩ.
BIAS Current Output
Truth Table
MOD+
(1)
MOD-
(2)
DIN+
DIN-
/EN
Laser Output
L
H
L
H
L
L
H
L
L
L
H
H
X
X
H
H
H
L
Notes:
1. IMOD = 0 when MOD+ = H.
2. Assuming that the laser cathode is tied to MOD+.
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SY88024L
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VIN) ..................................... –0.5V to +4.0V
CML Input Voltage (VIN) ....................VCC–1.2V to VCC+0.5V
TTL Control Input Voltage (VIN) ............................. 0V to VCC
Lead Temperature (soldering, 20sec.) ..................... +260°C
Storage Temperature (Ts) ......................... –65°C to +150°C
Supply Voltage (VCC)................................. +3.0V to +3.6V
Ambient Temperature (TA) ....................... –40°C to +85°C
(3)
Package Thermal Resistance
QFN
(θJA) Still-air .................................................... 60°C/W
(ψJB) ................................................................ 33°C/W
DC Electrical Characteristics
TA = –40°C to +85°C and VCC = +3.0V to +3.6V, unless otherwise noted. Typical values are VCC = +3.3V, TA = 25°C, IMOD = 6mA,
IBIAS = 6mA.
Symbol
Parameter
Condition
ICC
Power Supply Current
Modulation and bias currents
excluded
Min
Typ
VMOD_MIN
Minimum Voltage Required at the Driver
Output (headroom) for Proper Operation
1.2
V
VBIAS_MIN
Minimum Voltage Required at the BIAS
Output (headroom) for Proper Operation
1.2
V
RIN
Input Resistance, Single Ended
45
VID
Differential Input Voltage Swing
100
50
VIL
/EN Input Low
VIH
/EN Input High
2
IBIAS
Bias Current
1
IBias_OFF
Bias OFF Current
RMODSET
Input Resistance at MODSET Pin
VMODSET
Voltage Range at MODSET Pin
RBIASSET
Input Resistance at BIASSET Pin
VBIASSET
Voltage Range at BIASSET Pin
50
Max
65
Units
(4)
mA
55
Ω
1000
mVPP
0.8
Current at BIAS when the device is
disabled
20
mA
150
µA
25
IMOD range 2mA to 20mA
kΩ
1.2
25
IBIAS range 1mA to 20mA
V
V
V
kΩ
1.2
V
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Package Thermal Resistance assumes exposed pad is soldered (or equivalent) to the devices most negative potential on the PCB. θJB uses a
4-layer and θJA in still air unless otherwise stated.
4. Maximum ICC measured with IMOD = 20mA and IBIAS = 20mA and MOD+/MOD- tied to VCC.
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SY88024L
AC Electrical Characteristics
TA = –40°C to +85°C and VCC = +3.0V to +3.6V, unless otherwise noted. Typical values are VCC = +3.3V, TA = 25°C, IMOD = 6mA,
IBIAS = 6mA.
Symbol
Parameter
Condition
Data Rate
NRZ
Min
(5)
IMOD
Modulation Current
AC-coupled
IMOD_OFF
Modulation OFF Current
Current at MOD+ and MOD- when
the device is disabled
tr
Output Current Rise Time
20% to 80%, 25Ω load
tf
Output Current Fall Time
DJ
RJ
Typ
Max
Units
11.3
Gbps
(6)
mA
150
µA
25
35
ps
20% to 80%, 25Ω load
25
35
ps
Deterministic Jitter
K25.8 pattern at 11.3Gbps,
VIN = 200mVPP
4
psPP
Random Jitter
K25.8 pattern at 11.3Gbps,
VIN = 200mVPP
0.3
psPP
20
2
Notes:
5. IMOD is defined as the current going into the external load, which is equal to the total current of the output device subtracted by the current going into
the internal 50Ω pull-up.
6. IMOD(MAX) is defined for a 50Ω external load.
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SY88024L
Typical Characteristics
Modulation Gain
Bias Gain
IBIAS / IBIASMON vs IBIAS
40
120
30
35
110
25
30
100
25
20
20
15
90
80
15
70
10
10
60
5
5
50
2
5
10
15
20
25
IBIAS (mA)
0
100
0
200
400
600
800
VBIASSET (mV)
1000
15
250
550
850
1150
VMODSET (mV)
Note:
IMOD is defined for a 50Ω external load.
Functional Characteristics
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SY88024L
Input and Output Stages
Figure 1b. Simplified Output Stage
Figure 1a. Simplified Input Stage
Interfacing the Input to Differential Logic Drivers
Figure 2b. AC-Coupling to CML Driver
Figure 2a. AC-Coupling to LVPECL Driver
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SY88024L
Functional Diagram
composed from a differential pair which collectors are
connected to MOD+/MOD- pins and have 50
Ω internal
termination to VCC. The Modulation gain curve on page
6 shows modulation current variation versus the applied
voltage at MODSET pin.
Functional Description
As shown on the block diagram above, the driver is
composed from an input equalizer, and a modulation
block consisting of a pre-driver, and a current source.
Equalizer
The input equalizer allows for compensation of up to 9”
of FR4 microstrip trace or equivalent. The equalization
restores the losses in high frequency components of the
signal caused by its travel on the line card traces and
through the connectors between the line card and the
module before it reaches the input stage. The amount of
equalization is programmable with a resistor from pin 7
to ground.
Bias
The bias is set by applying a voltage within the range 0V
to 1.2V to pin 16 (BIASSET). The bias gain curve on
page 6 shows bias current variation versus the applied
voltage at pin 16.
The SY88024L driver is designed to work with one of the
Micrel’s MIC300X series of controllers which have built
in APC (Automatic Power Control) circuit and a serial
interface for programming modulation and bias,
temperature compensation tables, setting registers, and
monitoring registers read back. Refer to the
MIC3001/MIC3002/MIC3003 datasheets for more
details. The applications section below shows how to set
up the driver to work correctly with the MIC300X
controller.
Modulator
The modulator consists of a pre-driver and a current
source. The modulation current is set in the pre-driver by
applying a voltage within the range 0V to 1.2V to pin 5
(MODSET). The pre-driver provides the current to the
output stage, which consists of a current source
October 2009
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Micrel, Inc.
SY88024L
management IC MIC300X.
Application Information
Figure 3, below, illustrates a typical optical transceiver
using the SY88024L and one of the Micrel’s FOM
Figure 3. Typical Optical Transceiver
October 2009
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hbwhelp@micrel.com or (408) 955-1690
Micrel, Inc.
SY88024L
Package Information
16-Pin (3mm x 3mm) QFN
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
The information furnished by Micrel in
this data sheet 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 a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2009 Micrel, Incorporated.
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