SY88702KI TR Micrel Inc, SY88702KI TR Datasheet - Page 4

• Manufacturer Part Number: SY88702KI TR
• Description: IC LASR DRVR 622MBPS 5.5V 10MSOP
• Manufacturer: Micrel Inc
• Type: Laser Diode Driver (Fiber Optic)r

Specifications of SY88702KI TR

• Number Of Channels: 1
• Data Rate: 622Mbps
• Voltage - Supply: 4.5 V ~ 5.5 V
• Current - Supply: 16mA
• Current - Modulation: 25mA
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
• Mounting Type: Surface Mount
• Operating Supply Voltage (max): 5.5V
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: SY88702KITR; SY88702KITR

Micrel
50
through this load creates a voltage swing used to measure
various performance parameters of the SY88702. The
current is adjustable through the use of potentiometer R5.
The following sections detail various measurements that
can be performed with the SY88702 evaluation board:
[e-mail] or [phone]
MEASUREMENTS
The SY88702 evaluation board assumes the use of a
1. Eye pattern generation output including jitter, rise/fall
scope to terminate the SY88702. The current passing
times and modulation current verification:
a) Adjust R5 to give 1.25V (2.5V
b) Press Autoscale on oscilloscope. The eye
c) Observe measurements on scope’s display.
d) Adjust R5 to give 250mV (500mV
Figure 3. Typical SY88702 Eye Diagram
tude (I
be approximately 1k . The power supply needs
to be turned off to get a correct reading of the
potentiometer’s resistance.
pattern should automatically display on the scope.
If not, verify the steps listed in the “Setup for
Measurements” section are completed. Some-
times the waveform needs to be manually
adjusted to fit the display. Use the Time Scale and
Voltage Scale knobs on the front panel of the
scope to adjust this.
The rise and fall times should be less than 400ps,
amplitude around 1.25V and jitter around
10ps
amplitude (I
repeat above. R5 should be around 8k .
rms
mod
.
TIME (400ps/div.)
= 25mA = 1.25V/0.050k ). R5 should
mod
= 5mA = 0.250V/0.050 ) and
pp
) output ampli-
pp
) output
4
2. Mask testing:
3. BER testing:
a) Press eye/mask mode on front panel of scope
b) Choose mask testing from on-screen display
c) Choose open mask from on-screen selection list
d) Choose Start Mask Testing from on-screen
a) Since the SY88702 is designed to drive a laser,
b) Feedback the 70843V’s clock output to the
c) Set the 87702’s modulation current to a desired
d) From the 70004A’s Gating menu:
selection list. Waveform should automatically
display with appropriate mask regions and test-
ing will start. If not, verify the steps listed in the
“Setup for Measurements” section are completed.
where an optical HIGH means the laser is con-
ducting, the SY88702 will electrically be LOW.
Hence, the output polarity is opposite of the input
polarity. Since this is the case, it is recommended
to feedback the SY88702 evaluation board’s
/OUT output to the 70843B’s BERT data input.
The alternative is to feedback the SY88702
evaluation board’s OUT output to the 70843V’s
BERT data input, but to select inverted polarity
from the 70004A’s data menu.
70843V’s BERT clock input
value using R5 as described in Section 1 of this
page. Remember, I
iv. 70004A will reset error count and synchro-
iii. Choose run gating
v. At end of gating period, there should be no
ii. Choose single gating period
i. Select and open the OC-12 mask
i. Choose a gate condition. The options are:
gate by time, errors or bits. Choose bits, but
this is of no relevance because there should
be no errors, and the test will run forever until
manually interrupted if gate by errors is
chosen.
nize SY88702’s transmitted bitstream to
generated 70843V’s bitstream. If synchroni-
zation does not occur, it is sometimes due to
cable length. Try using different length cables
to achieve synchronization. If this is
unavailable, another trick is to adjust the
83752A’s frequency to a slightly higher or
lower value.
errors.
mod
SY88702 Evaluation Board
(mA) = V
amp
(V)/0.050k .