MAX3658AETA+T Maxim Integrated Products, MAX3658AETA+T Datasheet - Page 8

• Manufacturer Part Number: MAX3658AETA+T
• Description: IC AMP TRANSIMPEDANCE 8-TDFN
• Manufacturer: Maxim Integrated Products
• Type: Transimpedance Amplifierr

Specifications of MAX3658AETA+T

• Applications: Optical Networks
• Mounting Type: Surface Mount
• Package / Case: 8-TDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Select C
load resistors and coupling capacitors is much lower
than the low-frequency cutoff of the MAX3658. The cou-
pling capacitor should be 0.1µF or larger for SONET
data. For lowest jitter, 1.0µF is recommended. Refer to
application note HFAN-01.1: Choosing AC-Coupling
Capacitors for a more detailed discussion on choosing
AC-coupling capacitors.
Input sensitivity is improved by adding a filter between
TIA and the quantizer/limiting amplifier, with 0.5pF input
capacitance. Typical bandwidth of the MAX3658 is
580MHz; the highest expected bandwidth is 730MHz.
Figure 3 shows suggested layouts for 4- and 5-pin TO
headers.
For high-current density and reliable operation, the
MAX3658 uses gold metalization. For best results, use
gold-wire ball-bonding techniques. Use caution when
wedge bonding. Die-size is 52 mils x 29 mils, (1.32mm
x 0.736mm) and die thickness is 15 mils (380µm). The
bond-pad passivation opening is 75µm and bond-pad
metal thickness is 5µm. Refer to Maxim application note
HFAN-08.0.1: Understanding Bonding Coordinates and
Physical Die Size for additional information on bond-
pad coordinates.
Many of the MAX3658 specifications relate to the input
signal amplitude. When working with optical receivers,
the input is sometimes expressed in terms of average
optical power and extinction ratio. Figure 4 and Table 1
show relations that are helpful for converting optical
power to input signal when designing with the MAX3658.
The input-referred RMS noise current (i
MAX3658 generally determines the receiver sensitivity.
To obtain a system bit-error rate (BER) of 1E-10, the
signal-to-noise ratio must always exceed 12.7. The
input sensitivity, expressed in average power, can be
estimated as:
622Mbps, Low-Noise, High-Gain
Transimpedance Preamplifier
8
SENSITIVITY
_______________________________________________________________________________________
COUPLE
=
10
Applications Information
Optical Sensitivity Calculation
so the low-frequency cutoff due to the
log
⎛
⎜
⎜
⎝
12 7
2
.
Optical Power Relations
×
×
Layout Considerations
ρ
i
n
×
×
Select Output Filter
(
r
e
(
r
e
−
+
1
)
1
)
Wire Bonding
×
1000
n
⎞
⎟
⎟
⎠
dBm
) of the
Figure 3. Suggested TO Header Layouts
Table 1. Optical Power Relations*
* Assuming a 50% average mark density.
Average Power
Extinction Ratio
Optical Power of a 1
Optical Power of a 0
Optical Modulation
Amplitude
5-PIN HEADER
4-PIN HEADER
PARAMETER
OUT+
OUT+
MON
GND
SYMBOL
P
P
AVG
P1
P0
r
IN
e
PHOTODIODE
PHOTODIODE
MAX3658A
MAX3658A
GND
P
P
IN
P
1
C
C
AVG
VCC1
VCC1
P
=
=
=
V
0
V
OUT-
OUT-
CC
RELATION
CC
r
e
2
P
2
=
PHOTODIODE
MOUNTED ON C
OUTPUT POLARITIES
REVERSED FOR MAX3658B
CASE IS GROUND
PHOTODIODE
MOUNTED ON C
OUTPUT POLARITIES
REVERSED FOR MAX3658B
CASE IS GROUND
P
=
1
P
AVG
=
AVG
−
2
r
P
e
P
P
0
P
AVG
P
1
0
r
+
0
e
r
r
+
2
e
e
FILT
FILT
r
1
e
+
−
+
P
1
1
1
1