Microcosm
F
EATURES
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Low-cost IC, fabricated in advanced sub-
micron BiCMOS process
Designed for driving VCSELs and low
current Fabry Perot lasers
Very wide range of operation; suitable for
<100Mbps to 1.25Gbps applications
Rise/fall times <250ps
Independently programmable VCSEL bias
and modulation currents
Bias current up to 20mA and modulation
current up to 40mA at V
CC
=3.3V
Open and closed loop configuration
Operates with standard 5V or 3.3 V supply
(±10%)
The MC2062 is available in TSSOP24 and
QSOP16 packages, or in die form
MC2062
D
ESCRIPTION
The MC2062 is a highly integrated, programmable
laser driver for fiber optic communications systems
operating at up to 1.25Gbps. Both 3.3V and 5V op-
eration are supported.
The MC2062 has differential PECL data inputs and
CMOS control inputs. The modulation current and
temperature coefficient are programmed by the se-
lection of resistor values. The bias current may be
controlled in a servo loop, using a feedback
photodetector. Alternatively, the bias current and
temperature coefficient may be programmed using
external resistors.
The MC2062 includes circuits to monitor the opera-
tion of the bias current control loop and to monitor
the power supply level. These are used to control a
safety logic function. The safety logic output on the
FAILOUT pin indicates when failure of the bias con-
trol loop is detected.
On the QSOP16 package, the FAILOUT pin is inter-
nally bonded to the DISABLE pad on the die. The
output is always disabled when the control loop fails.
3.3 to 5V Laser/VCSEL Driver IC for Applications from 100Mbps to 1.25Gbps
A
PPLICATIONS
G
G
G
Gigabit Ethernet
Fiber Channel 100
Fast Ethernet
Part
MC2062DIE
MC2062DIEW
MC2062T24
MC2062T24TR
MC2062Q16
MC2062Q16TR
O
RDERING
I
NFORMATION
Pin-Package
Waffle pack
Expanded Whole Wafer on a Ring
TSSOP24
TSSOP24 Tape and Reel
QSOP16
QSOP16 Tape and Reel
C
ONNECTIONS
GND
3
RE-
SET
T
OP
L
EVEL
D
IAGRAM
B2
C2
I
M O D S E T
V
CCA
V
CCA
TSSOP24
C2
B2
RESET
GND
GND
D
IN
D
IN
ENABLE
DISABLE
1
2
3
4
5
6
7
8
9
24
23
22
21
20
QSOP16
IMODSET
V
CCA
V
CCA
V
CCO
OUT2P
OUTP
OUT2N
OUTN
GND
I
PIN
I
BIASSET
I
BIASOUT
C2
B2
RESET
GND
D
IN
D
IN
ENABLE
FAILOUT
1
2
3
4
5
6
7
8
16
15
14
I
MODSET
V
CCA
V
CCO
OUTP
OUTN
GND
I
PIN
I
BIASOUT
GND
2
V
CCO
D
IN
Microcosm
MC2062
Datecode
19
18
17
16
15
14
13
Microcosm
MC2062
Datecode
13
12
11
10
9
MODULATOR
D
IN
OUT
2P
OUT
P
FAILOUT
10
B1
11
E1
12
EN-
ABLE
SAFETY
LOGIC
OUT
2N
BIAS
OUT
N
6.5x4.4mm
4.3x3.9mm
DIS-
ABLE
FAIL
OUT
B1
E1
I
B I A S O U T
I
BIASSET
I
P I N
GND
0
PRELIMINARY INFORMATION
PAGE -1-
MC2062_F
MC2062
3.3 to 5V Laser/VCSEL Driver IC for Applications from 100Mbps to 1.25Gbps
P
IN
D
ESCRIPTION
Pin Name
C2
B2
RESET
GND
GND
D
IN
D
IN
ENABLE
DISABLE
FAILOUT
B1
E1
I
BIASOUT
I
BIASSET
I
PIN
GND
OUTN
OUT2N
OUTP
OUT2P
V
CCO
V
CCA
V
CCA
I
MODSET
1
16 QSOP
Pin No.
1
2
3
-
4
5
6
7
-
8
(1)
-
-
9
-
10
11
12
12
13
13
14
-
15
16
20 TSSOP
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Function
NPN collector. Used in conjunction with B2 for temperature
compensation of modulation current.
NPN base. Used in conjunction with C2 for temperature
compensation of modulation current.
Value of capacitor connected to this internal resistor
determines length of reset pulse to latch.
Ground pin.
Ground pin
Non-inver ted data input. May be AC-coupled or directly
coupled to differential PECL source.
Inver ted data input. May be AC-coupled or directly coupled to
differential PECL source.
CMOS logic input. On-chip pull-up.
CMOS logic input. On-chip pull-down.
Latched safety logic output.
NPN base. Used in conjunction with E1 for temperature
compensation of bias current in open loop operation
NPN emitter. Used in conjunction with B1 for temperature
compensation of bias current in open loop operation.
Bias current output.
Reference current output for control of bias current when
feedback photodetector is not used.
Control input for bias current control circuit.
Ground pin.
Modulator output. Draws current when D
IN
=0.
Modulator output. Draws current when D
IN
=0.
Modulator output. Draws current when D
IN
=1.
Modulator output. Draws current when D
IN
=1.
Positive supply for modulator and bias circuit outputs.
Positive supply for circuits other than modulator and bias
outputs.
Positive supply for circuits other than modulator and bias
outputs.
Control input for modulation current setting circuit.
Failout is connected to Disable internal to the QSOP16 package. As a result, a fault condition will disable the
laser drive circuitry.
PRELIMINARY INFORMATION
PAGE -2-
MC2062_F
MC2062
3.3 to 5V Laser/VCSEL Driver IC for Applications from 100Mbps to 1.25Gbps
A
BSOLUTE
M
AXIMUM
R
ATINGS
Symbol
V
CC
T
A
T
STG
Parameter
Power Supply (V
CC
-Gnd)
Operating ambient
Storage temperature
Rating
6
-40 to +85
-65 to +150
Units
V
°C
°C
R
ECOMMENDED
O
PERATING
C
ONDITIONS
Symbol
V
CC
T
A
1
Parameter
Power supply (V
CC
-GND)
Operating ambient
Rating
3 to 5.5
-40 to +85
(1)
Units
V
°C
Check with Microcosm for allowable combinations of package/thermal resistance, power supply voltage and
drive currents.
AC C
HARACTERISTICS
Symbol
I
MODOUT
Parameter
Modulation current available at each
output
Min.
40
Typ.
-
Max.
-
Units
mApp
Modulation current into VCSEL
I
MOD
(VCSEL) Z
VCSEL
=50
Ω
Z
VCSEL
=25
Ω
t
R
, t
F
Modulation current rise/fall times (10-90%
points) at modulator output pins with
loads of 50
Ω
to positive supply.
Range of programmable temperature co-
efficient on modulation current.
Modulation current pulse width distortion
Modulation current multiplier
Modulation current offset
-
16
26
-
-
mApp
-
250
ps
TC
IOUT
t
PWD
M
IMOD
C
IMOD
1
-250
(1)
-
-
-
-
-
96
-2
>10,000
TBD
-
-
ppm/°C
%
A/A
mA
This is the value with no external temperature compensation set.
PRELIMINARY INFORMATION
PAGE -3-
MC2062_F
MC2062
3.3 to 5V Laser/VCSEL Driver IC for Applications from 100Mbps to 1.25Gbps
DC C
HARACTERISTICS
Symbol
R
IN
R
N
, R
P
V
IH
V
IL
V
CIH
V
CIL
I
CC
I
BIAS
TC
BIASOUT
V
SUPTH
V
REF1
V
REF2
V
REF3
V
REF4
M
IBIAS
R
RESET
C
IBIAS
1
Parameter
On-chip resistance D
IN
to D
IN
(for
impedance matching to input bond wires)
On-chip modulator pull-up resistors.
(1)
PECL Input High
PECL Input Low
Enable and Disable Input High
Enable and Disable Input Low
Supply current
Maximum programmable bias current
Range of programmable temperature co-
efficient on Bias Current (open loop
operation)
Supply detection threshold.
Voltage ref. used for mod current control
Voltage ref. used for bias current control
Upper voltage ref. used to monitor bias
control loop.
Lower voltage ref.used to monitor bias
control loop
Bias current multiplier
Pull-up resistor connected to RESET pin
Bias current offset.
Min.
-
65
V
CC
-1150
V
CC
-1900
-
-
-
20
-1,000
(2)
-
1.15
V
CCA
-1.25
V
CCA
-1.15
V
CCA
-1.35
-
400
-
Typ.
600
75
-
-
0.66xV
CC
0.33xV
CC
I
MOD
+
I
BIAS
+14mA
-
-
2.4
1.2
V
CCA
-1.2
V
CCA
-1.1
V
CCA
-1.3
39
500
-1
Max.
-
85
V
CC
-800
V
CC
-1500
-
-
-
-
>20,000
-
1.25
V
CCA
-1.15
V
CCA
-1.05
V
CCA
-1.25
-
600
-
Units
Ω
Ω
mV
mV
V
V
mA
mA
ppm/°C
V
V
V
V
V
A/A
kΩ
mA
The value of this on-chip resistor is mask-programmable. Contact Microcosm for details on how to match this
value to your desired VCSEL.
2
This is the value with no external compensation set.
PRELIMINARY INFORMATION
PAGE -4-
MC2062_F
MC2062
3.3 to 5V Laser/VCSEL Driver IC for Applications from 100Mbps to 1.25Gbps
T
YPICAL
P
ERFORMANCE
C
URVES
Bias Current vs Bias Setting Resistance
25
5
4
14
Bias Current vs Bias Setting Current
12
2
20
0
0
10
Bias Current (mA)
15
5
Bias Current (mA)
8
8
10
0
6
6
4
4
5
5
2
2
0
0
0
5
10
15
Bias Setting Resistance (kΩ)
20
25
0
0
0
0.05
0.1
0.15
0.2
Bias Setting Current (mA)
0.25
0.3
0.35
Open Loop Bias Current with Temperature
25
5
Modulation Current vs Modulation Setting
Resistance
35
30
0
5
20
0
Modulation Current (mA)
Temp -40C
Temp +85C
5
25
Bias Current (mA)
15
5
0
20
10
0
5
15
0
10
5
5
5
5
0
0
0
0
2
3
4
5
6
7
8
Bias Setting Resistance (kΩ)
9
10
11
12
0
5
10
15
20
Modulation Setting Current (kΩ)
25
30
Modulation Current vs Modulation Setting
Current
2
24
0
20
Modulation Current (mApp)
16
8
12
6
4
8
2
4
0
0
0
0.02
0.04
0.06
0.08
0.10
Modulation Setting Current (mA)
0.12
0.14
PRELIMINARY INFORMATION
PAGE -5-
MC2062_F
