MAX3273ETG+T Maxim Integrated Products, MAX3273ETG+T Datasheet - Page 11

• Manufacturer Part Number: MAX3273ETG+T
• Description: IC LASR DRVR 2.7GBPS 3.6V 24TQFN
• Manufacturer: Maxim Integrated Products
• Type: Laser Diode Driver (Fiber Optic)r

Specifications of MAX3273ETG+T

• Data Rate: 2.7Gbps
• Number Of Channels: 1
• Voltage - Supply: 3.14 V ~ 3.6 V
• Current - Supply: 30mA
• Current - Modulation: 60mA
• Current - Bias: 100mA
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 24-TQFN Exposed Pad
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 1. Optical Power Relations
Note: Assuming a 50% average input duty cycle and mark density.
An example of how to set up the MAX3273 follows.
A communication-grade laser should be selected for
2.5Gbps/2.7Gbps applications. Assume the laser out-
put average power is P
ratio is r
-40°C to +85°C, and the laser diode has the following
characteristics:
•
•
•
•
•
The desired monitor diode current is estimated by I
= P
in the Typical Operating Characteristics shows that
R
APCSET
Average Power
Extinction Ratio
Optical Power of a 1
Optical Power of a 0
Optical Amplitude
Laser Slope Efficiency
Modulation Current
Threshold Current
Bias Current
Laser-to-Monitor Transfer
AVG
Wavelength: λ = 1310nm
Threshold Current: I
Threshold Temperature Coefficient: β
Laser-to-Monitor Transfer: ρ
Laser Slope Efficiency: η = 0.05mW/mA at +25°C
× ρ
e
should be 7.5kΩ.
PARAMETER
= 6.6 (8.2dB), the operating temperature is
MON
Applications Information
= 200µA. The I
______________________________________________________________________________________
+3.3V, 2.5Gbps Low-Power Laser Driver
AVG
TH
= 22mA at +25°C
= 0, the minimum extinction
Determine R
MON
MD
vs. R
= 0.2A/W
SYMBOL
ρ
P
I
I
P
MOD
BIAS
Select Laser
I
MON
AVG
P
P
r
TH
P-P
η
e
TH
1
0
APCSET
= 1.3%/°C
APCSET
graph
MD
To achieve a minimum extinction ratio (r
temperature and lifetime, calculate the required extinc-
tion ratio at +25°C. Assuming r
optical power P
The required modulation current is 1.81mW/
(0.05mW/mA) = 36.2mA. The I
in the Typical Operating Characteristics shows that
R
Calculate the maximum threshold current (I
T
50mA, the maximum bias current should be: I
= I
68.1mA. The I
Typical Operating Characteristics shows that R
should be 3.5kΩ.
A
MODSET
TH(MAX)
= +85°C and end of life. Assuming I
P
P-P
should be 5kΩ.
= P
+ (I
P
1
I
P
P
1
BIAS
- P
0
AVG
= 2P
MOD
BIASMAX
η = P
I
= 2P
P-P
MOD
0
P
RELATION
r
I
≥ I
e
= 2P
0
MD
= (P
AVG
= P
at 1 ≥ I
= 1.81mW, according to Table 1.
AVG
TH
P-P
= P
/ 2). In this example, I
/ P
AVG
0
1
r
+ I
e
/ I
AVG
P-P
+ P
/ P
/ (r
/ (r
MOD
MOD
TH
vs. R
(r
0
e
/ η
1
e
e
) / 2
+ 1)
Determine R
- 1) / (r
+ 1)
Determine R
/ 2
MOD
e
BIASMAX
= 20, the peak-to-peak
e
vs. R
+ 1)
MODSET
e
graph in the
) of 6.6 over
TH(MAX)
TH(MAX)
BIASMAX
BIASMAX
MODSET
BIASMAX
BIASMAX
graph
) at
11
=
=