SY84782U
Low Power 2.5V 1.25Gbps FP/DFB Laser
Diode Driver
General Description
Features
The SY84782U is a single 2.5V supply, ultra-low power,
•
2.5V power supply option
small form factor laser diode driver for telecom/datacom
•
Ultra low power consumption (63mW typ)
applications. Intended to drive FP/DFB lasers at data rates
•
Multirate up to 1.25Gbps
up to 1.25Gbps, it is especially useful for Compact SFP,
•
Fast rise and fall time
SFP, and SFF modules where power requirements are
•
Modulation current up to 90mA
quite stringent. The driver can deliver modulation current
up to 90mA and offers a high compliance voltage, all of
•
Laser can be DC- or AC-coupled
which make the SY84782U suitable for high current
•
Small form factor 16-pin (3mm × 3mm) QFN package
operations in both AC- and DC-coupled applications.
•
MIC3003G compatible
The SY84782U is intended to be used with Micrel’s
•
Extensive temperature range (–40°C to +95°C)
MIC3003 Optical Transceiver Management IC, which
allows for both modulation and bias current control and
Applications
monitoring. Furthermore, the MIC3003 offers power control
•
Multirate LAN, MAN applications: Fibre Channel, GbE,
and temperature compensation.
SONET OC3/12/24, and SDH STM1/4/8
This device operates across the industrial temperature
•
CSFP/SFF/SFP optical modules
range (–40°C to +95°C) and is available in a small 3mm ×
3mm QFN package.
All datasheets and support documentation can be found
on Micrel’s website at:
www.micrel.com.
___________________________________________________________________________________________________________
Typical Application
DC-Coupled Laser
AC-Coupled Laser
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
August 11, 2015
Revision 2.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY84782U
Ordering Information
Part Number
SY84782UMG
SY84782UMG TR
Note:
1.
Tape and Reel
(1)
Package Type
QFN-16
QFN-16
Operating Range
Industrial
Industrial
Package Marking
782U Pb-Free Bar-Line Indicator
782U Pb-Free Bar-Line Indicator
Lead Finish
Pb-Free
Pb-Free
Pin Configuration
16-Pin QFN
Pin Description
Pin Number
1, 4, 7,
8, 13
2
3
5, 6
9, 10
11, 12
14
15
16
Pin Name
GND,
ePad
DIN+
DIN-
VCC
MOD-
MOD+
VREF
IM_SET
/EN
Pin Function
Device Ground. Ground and exposed pad must be connected to the plane of the most negative
potential.
Non-Inverting Input Data. Internally terminated with 50Ω to a reference voltage
Inverting Input Data. Internally terminated with 50Ω to a reference voltage
Supply Voltage. Bypass with a 0.1µF || 0.01µF low-ESR capacitor as close to VCC pin as possible.
Inverted Modulation Current Output. Provides modulation current when input data is negative
Non-Inverted Modulation Current Output. Provides modulation current when input data is positive.
Reference Voltage. Install a 0.1µF capacitor between VREF and VCC
Modulation current setting and control. The voltage applied to this pin will set the modulation current.
To be connected to the MIC3003 Pin 24 (VMOD+). Input impedance 25kΩ.
Enable Pin. A high level signal applied to this pin will pull the MOD+ output HIGH and MOD- output
LOW. Internally pulled down with a 75kΩ resistor.
Truth Table
DIN+
L
H
X
DIN-
H
L
X
/EN
L
L
H
MOD+
H
L
H
(2)
MOD-
L
H
L
Laser Output
L
H
L
(3)
Notes:
2. I
MOD
= 0 when MOD+ = H.
3. Assuming that laser is tied to MOD+.
August 11, 2015
2
Revision 2.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY84782U
Absolute Maximum Ratings
(4)
Supply Voltage (V
CC
) .................................. –0.5V to +3.0V
Input Voltage (V
IN
) .......................................... –0.5V to V
CC
TTL Control Input Voltage (V
IN
) ........................... 0V to V
CC
Lead Temperature (soldering, 20s) .......................... +260°C
Storage Temperature (T
S
) ....................... –65°C to +150°C
Operating Ratings
(5)
Supply Voltage (V
CC
) .............................. 2.375V to 2.625V
Ambient Temperature (T
A
) ......................... –40°C to +95°C
(6)
Package Thermal Resistance
Still-Air (θ
JA
) ....................................................... 60°C/W
Junction-to-Board (Ψ
JB
)..................................... 33°C/W
DC Electrical Characteristics
(7)
V
CC
= 2.5V ±5%, T
A
= –40°C to +95°C. Typical values are V
CC
= 2.5V, T
A
= 25°C, I
MOD
= 60mA.
Symbol
I
CC
V
MOD_MIN
R
iIN(DATA)
R
iIN(IMOD_SET)
V
ID
V
IH_EN
V
IL_EN
V
IM_SET
Parameter
Power Supply Current
Minimum voltage required
at driver output for proper
operation
Input Resistance (DIN+, DIN-)
Input Resistance (IM_SET)
Differential Input Voltage Swing
/EN Input High
/EN Input Low
Voltage Range on IM_SET Pin
I
MOD
range 10mA – 90mA
200
2
0.8
1.2
Condition
Modulation current excluded
0.6
45
50
25
2400
55
Min.
Typ.
24
Max.
30
(8)
Units
mA
V
Ω
kΩ
mVpp
V
V
V
AC Electrical Characteristics
(7)
V
CC
= 2.5V ±5%, T
A
= –40°C to +95°C. Typical values are V
CC
= 2.5V, T
A
= 25°C, I
MOD
= 60mA.
Symbol
Parameter
Data Rate
I
MOD
I
MOD_OFF
Modulation Current
(15Ω Load)
Modulation OFF current
Total Jitter
Pulse-Width Distortion
t
r
, t
f
Notes:
4. Exceeding the absolute maximum rating may damage the device.
5. The device is not guaranteed to function outside its operating rating.
6. Package thermal resistance assumes exposed pad is soldered (or equivalent) to the devices most negative potential on the PCB.
7. Specification for packaged product only.
8. Icc = 30mA (excluding I
MOD
) for worst case conditions with V
CC
= 2.625V, T
A
= 85°C, I
MOD
= 60mA.
9. Assuming V
CC
= 2.375V, laser band gap voltage = 1V, laser package inductance = 1nH, laser equivalent series resistor = 5Ω, and damping resistor =
10Ω.
Condition
NRZ Data
AC-Coupled
DC-Coupled
Current at MOD+ when the
device is disabled
@ 1.25Gbps data rate
I
MOD
range 10mA – 90mA
15Ω Load
Min.
0.155
10
10
Typ.
Max.
1.25
90
70
(9)
Units
Gbps
mA
µA
pspp
ps
ps
750
20
20
100
140
Output Rise/Fall Times
(20% to 80%)
August 11, 2015
3
Revision 2.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY84782U
Typical Operating Characteristics
V
CC
= 2.5V ±5%, T
A
= –40°C to +95°C. Typical values are V
CC
= 2.5V, T
A
= 25°C, I
MOD
= 60mA.
IM_SET vs Modulation Current
100
90
80
70
Supply Current vs I
MOD
(I
MOD
Excluded)
30
100
90
80
70
I
MOD
vs V
MOD
(Compliance Voltage)
Supply Current (mA)
25
I
MOD
(mA)
IMOD (mA)
60
50
40
30
20
10
0
0
200
400
600
800
1000
IM_SET Voltage (mV)
60
50
40
30
20
10
0
20
15
10
0
10
20
30
40
50
60
70
80
90 100
Modulation Current (mA)
0
0.2
0.4
0.6
V
MOD
(V)
0.8
1
1.2
Functional Block Diagram
August 11, 2015
4
Revision 2.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY84782U
Functional Characteristics
V
CC
= 2.5V ±5%, T
A
= –40°C to +95°C. Typical values are V
CC
= 2.5V, T
A
= 25°C, I
MOD
= 60mA.
Input and Output Stages
Figure 1. Simplified Input Stage
Figure 2. Simplified Output Stage
August 11, 2015
5
Revision 2.0
hbwhelp@micrel.com
or (408) 955-1690
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