Preliminary
13
Typical Applications
• Quad-Channel Gigabit and 10Gigabit
Ethernet Optical Transceivers
• CWDM/WWDM 4-Channel Parallel Links
RF3754
QUAD-CHANNEL VCSEL LASER DRIVER
(4x3.125Gbps)
• SONET VSR & System Interconnect
• All Fiber Optic Transceiver Applications up
to 3.125Gbps Serial Data Rate
Product Description
The RF3754 is a quad-channel integrated laser driver
intended to drive an 850nm VCSEL. The RF3754 fea-
tures four differential input and single-ended output opti-
mized for line rates of 2.5Gbps to 3.125Gbps with low
power consumption. All four channels operate with +3.3V
and 264mΩ quiescent power dissipation. Laser bias is
supplied from 2mA to 25mA per channel and modulating
currents from 1mA to 18mA per channel. The device may
be used in 4-fiber or 4-wavelength quad-channel fiber
optic transceiver applications operating up to
3.125Gbps/channel. The RF3754 contains a bias gener-
ator, laser modulator, and failure alarm. APC maintains
constant average optical output power by adjusting the
laser bias current to offset temperature effects and laser
aging. The RF3754 is available in bare die configuration.
Optimum Technology Matching® Applied
Si BJT
Si Bi-CMOS
GaInP/HBT
GaAs HBT
GaN HEMT
GaAs MESFET
Si CMOS
SiGe Bi-CMOS
2.67
Die Thickness: 0.3 mm
Dimensions in mm
1.70
Package Style: Bare Die
!
SiGe HBT
Features
• +3.3V Supply Voltage, 80mA Quiescent
Current
13
OPTICAL
COMMUNICATIONS
Ch 1
• Common Cathode Laser Driver
• 1mA to 18mA Laser Modulation Current
• 2mA to 25mA Laser Bias Current Control
Range
Ch 2
Ch 3
Ch 4
Ordering Information
RF3754
Quad-Channel VCSEL Laser Driver (4x3.125Gbps)
Failure
Alarm
FA
1
FA
2
FA
3
FA
4
Functional Block Diagram
RF Micro Devices, Inc.
7628 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
Rev A1 020710
13-1
RF3754
Absolute Maximum Ratings
Parameter
Rating
Unit
Preliminary
Supply Voltage
4
V
DC
Input Voltage
4
V
P-P
Operating Ambient Temperature
-40 to +85
°C
Storage Temperature
-65 to +125
°C
Junction Temperature
+125
°C
Note: TA=+25°C unless otherwise noted. Functional operation near or
above Maximum Ratings is not implied. Exposure to stress levels at or
near maximum ratings for any period of time may affect reliability or
cause permanent damage to the devices.
Caution!
ESD sensitive device.
RF Micro Devices believes the furnished information is correct and accurate
at the time of this printing. However, RF Micro Devices reserves the right to
make changes to its products without notice. RF Micro Devices does not
assume responsibility for the use of the described product(s).
Parameter
Inputs
Data Rate, BR
Supply Voltage, V
Quiescent Current, I
Q
Total Current, I
TOT
Differential Input Impedance, R
IN
Differential Input V Swing,
V
INDIFF
Specification
Min.
Typ.
Max.
0.1
3.0
3.125
3.3
20
80
30
100
4
3.6
25
68
110
1500
Unit
Condition
T=25 °C, V
CC
=3.3V, V
IN
=500mV
P-P
,
Data Rate=3.125Gbps, Single Channel
16
90
50
Gbps
V
mA
mA
mA
Ω
mV
P-P
All four channels powered on
I
TOT
=I
Q
+I
BIAS
+I
MOD
Outputs
Laser Bias Current, I
BIAS
Laser Modulation Current, I
MOD
Output Rise/Fall Time,
t
rOUT
, t
fOUT
Output Skew, dt
Latency
Output Random Jitter, RJ
P-P
Output Undershoot/Overshoot
Alarm Out Hi, Alrm
Alarm Out Low, Alrm
Time to Enable, T
ON
Time to Disable, T
OFF
Time to Fault, T
FAULT
Crosstalk
2
1
50
15
10
V
CC
Gnd
0.005
8
5
PASS
25
18
70
20
20
20
mA
mA
pS
pS
pS
%
Ext R Bias Set
Ext R Modset
Electrical Rise and Fall Time at 10%/90%
13
OPTICAL
COMMUNICATIONS
1
10
50
mS
uS
uS
Mask test with 20dB adjacent channel to
input channel power ratio tolerance.
Current Control
Laser Bias Current
Control Range, R
BIAS
Laser Modulation Current
Control Range, R
MOD
2000
0
20,000
10,000
Ω
Ω
Ext R Bias Set
Ext R Modset
Laser Alarm Table
TX Disable
0V to 1.3V
0V to 1.3V
1.4V to V
CC
System State
Normal
Failure of Photo or Laser Diode
N/A
Alarm Out
Gnd
V
CC
V
CC
13-2
Rev A1 020710
Preliminary
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Function
VCC
IN+ 1
IN- 1
AC GND
VCC
IN+ 2
IN- 2
AC GND
VCC
IN+ 3
IN- 3
AC GND
VCC
IN+ 4
IN- 4
AC GND
VREF4
MOD SET4
LOOP
CONSTANT1
VREF1
GND
MOD SET1
LOOP
CONSTANT2
VREF2
GND
MOD SET2
LOOP
CONSTANT3
VREF3
MOD SET3
LOOP
CONSTANT4
LASER MOD4
LASER DC4
PD IN4
Description
Voltage supply, +3.3V
Input pin for channel 1, positive polarity of differential pair.
Input pin for channel 1, negative polarity of differential pair.
DC voltage is present on this pin. When grounding this pin,
a DC blocking capacitor must be used.
Voltage supply, +3.3V
Input pin for channel 2, positive polarity of differential pair.
Input pin for channel 2, negative polarity of differential pair.
DC voltage is present on this pin. When grounding this pin,
a DC blocking capacitor must be used.
Voltage supply, +3.3V
Input pin for channel 3, positive polarity of differential pair.
Input pin for channel 3, negative polarity of differential pair.
DC voltage is present on this pin. When grounding this pin,
a DC blocking capacitor must be used.
Voltage supply, +3.3V
Input pin for channel 4, positive polarity of differential pair.
Input pin for channel 4, negative polarity of differential pair.
DC voltage is present on this pin. When grounding this pin,
a DC blocking capacitor must be used.
On-chip reference voltage for channel 4.
Sets laser modulation current for channel 4 by external
resistor or potentiometer.
Control loop capacitor, maintain loop constant on channel
1.
On-chip reference voltage for channel 4.
Ground connection. For best results, keep traces physically
short and connect immediately to ground plane.
Sets laser modulation current for channel 1 by external
resistor or potentiometer.
Control loop capacitor, maintain loop constant on channel
2.
On-chip reference voltage for channel 2.
Ground connection. For best results, keep traces physically
short and connect immediately to ground plane.
Sets laser modulation current for channel 2 by external
resistor or potentiometer.
Control loop capacitor, maintain loop constant on channel
3.
On-chip reference voltage for channel 3.
Sets laser modulation current for channel 3 by external
resistor or potentiometer.
Control loop capacitor, maintain loop constant on channel
4.
Laser modulation current for channel 4.
DC laser bias current for channel 4.
Input from anode of photodiode for control loop for channel
4.
RF3754
Bond Pad Center Coordinates
(xmm, ymm)
(0,2.22)
(0,2.09)
(0,1.97)
(0,1.84)
(0,1.66)
(0,1.54)
(0,1.41)
(0,1.29)
(0,1.11)
(0,0.99)
(0,0.86)
(0,0.74)
(0,0.56)
(0,0.44)
(0,0.31)
(0,0.19)
(0,0.06)
(0.13,0)
(0.25,0)
(0.38,0)
(0.50,0)
(0.63,0)
(0.75,0)
(0.88,0)
(1.00,0)
(1.13,0)
(1.25,0)
(1.38,0)
(1.50,0)
(1.55,0.19)
(1.55,0.31)
(1.55,0.44)
(1.55,0.56)
13
OPTICAL
COMMUNICATIONS
Rev A1 020710
13-3
RF3754
Pin
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
Pkg
Base
Function
LASER MOD3
LASER DC3
PD IN3
LASER MOD2
LASER DC2
PD IN2
LASER MOD1
LASER DC1
PD IN1
ALARM OUT4
ALARM OUT3
ALARM OUT2
ALARM OUT1
GND
GND
TX DISABLE1
TX DISABLE2
TX DISABLE3
TX DISABLE4
GND
Description
Laser modulation current for channel 3.
DC laser bias current for channel 3.
Input from anode of photodiode for control loop for channel
3.
Laser modulation current for channel 2.
DC laser bias current for channel 2.
Input from anode of photodiode for control loop for channel
2.
Laser modulation current for channel 1.
DC laser bias current for channel 1.
Input from anode of photodiode for control loop for channel
1.
Alarm signal for channel 4.
Alarm signal for channel 3.
Alarm signal for channel 2.
Alarm signal for channel 1.
Ground connection. For best results, keep traces physically
short and connect immediately to ground plane.
Ground connection. For best results, keep traces physically
short and connect immediately to ground plane.
Disables laser driver channel 1 output.
Disables laser driver channel 2 output.
Disables laser driver channel 3 output.
Disables laser driver channel 4 output.
Ground connection. For best results, keep traces physically
short and connect immediately to ground plane.
Preliminary
Bond Pad Center Coordinates
(xmm, ymm)
(1.55,0.86)
(1.55,0.98)
(1.55,1.11)
(1.55,1.41)
(1.55,1.54)
(1.55,1.66)
(1.55,1.97)
(1.55,2.09)
(1.55,2.22)
(1.55,2.34)
(1.38,2.49)
(1.25, 2.49)
(1.13,2.49)
(1.00,2.49)
(0.88,2.49)
(0.38,2.49)
(0.25,2.49)
(0.13,2.49)
(0,2.49)
13
OPTICAL
COMMUNICATIONS
13-4
Rev A1 020710
Preliminary
Die Package Drawing
0.00
0.13
0.25
0.38
0.88
1.00
1.13
1.25
1.38
2.49
2.22
2.09
1.97
1.84
1.66
1.54
1.41
1.29
2.67
1.11
0.99
0.86
0.74
0.56
0.44
0.21
0.19
0.06
0.00
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
0.00
33
32
31
30
0.56
0.44
0.21
0.19
52
1
2
3
4
5
6
7
8
Die Thickness 0.3 mm
Dimensions in mm
51
50
49
48
47
46
45
44
43
42
41
40
1.55
2.49
2.34
2.22
2.09
1.97
RF3754
39
38
37
1.64
1.54
1.41
36
35
34
1.11
0.99
0.86
0.00
0.13
0.25
0.38
0.50
0.63
0.75
0.88
1.00
1.13
1.25
1.38
1.70
Detailed Functional Block Diagram
ALARM OUT1
ALARM OUT2
ALARM OUT3
44
43 ALARM OUT4
LD
42 PD IN1
41 LASER DC1
40 LASER MOD1
TX DISABLE4
TX DISABLE3
TX DISABLE2
TX DISABLE1
GND
GND
52
VCC 1
IN+ 1 2
IN- 1 3
AC GND 4
VCC 5
IN+ 2 6
IN- 2 7
AC GND 8
VCC 9
IN+ 3 10
IN- 3 11
AC GND 12
VCC 13
IN+ 4 14
IN- 4 15
AC GND 16
VREF4 17
51
50
49
48
47
46
45
1.55
1.50
13
OPTICAL
COMMUNICATIONS
LD
39 PD IN2
38 LASER DC2
37 LASER MOD2
LD
36 PD IN3
35 LASER DC3
34 LASER MOD3
33 PD IN4
LD
32 LASER DC4
31 LASER MOD4
30
LOOP
CONSTANT4
18
MOD SET4
19
LOOP
CONSTANT1
20
VREF1
21
GND
22
MOD SET1
23
LOOP
CONSTANT2
24
VREF2
25
GND
26
MOD SET2
27
LOOP
CONSTANT3
28
VREF3
29
MOD SET3
Rev A1 020710
13-5
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