GD90573A Intel, GD90573A Datasheet - Page 2

• Manufacturer Part Number: GD90573A
• Manufacturer: Intel

Specifications of GD90573A

• Lead Free Status / Rohs Status: Not Compliant

Functional Details
Power Supply
A single supply voltage of –7.5 V drives
the board. Higher supply voltage can be
used if a heat sink is mounted on the
voltage regulator (U2).
Data Input
The data input to the Laser Driver is
differential and AC coupled, with the two
inputs found in J2 and J3. Single-ended
application can be obtained easily by
connecting a 50 W terminator to the un-
used input connector.
The differential data inputs are termi-
nated internally in the Laser Driver with
50 W to DINT/DINTQ.
Data Output
The modulation current from the laser
driver (IOUT/IOUTN) is fed to the laser
unit via transmission lines to J5 at the
board edge. For easy electrical testing of
output SMA connectors are mounted on
the board when delivered from factory.
The footprint of J5 is intended for con-
nection to the RF side of butterfly pack-
age. When using the board with a laser
unit desolder the SMA connectors in J5.
At delivery the outputs are DC-connected
(C2 and C3 are 0 W). If AC-coupling is
preferred replace these components with
SMD capacitors (size 0603) and connect
the IOUT/IOUTN pins to VDD via
RF- chokes. Refer to Data Sheet for
GD16573A for further information.
Regulation Circuit
Modulation Regulation
The GD90573A evaluation board com-
prises a regulation network for the modu-
lation current.
This regulation circuit comprises a simple
external filter and feed-back loop to the
laser driver’s integrated regulation net-
work.The regulation is included to stabi-
lise the modulation current, independent
of load variations in the laser or drift in la-
ser driver.
The modulation current is monitored
across R6 by the op-amp in U4:A. The
feedback regulation signal is low pass fil-
tered and routed out to jumper J7 . The
signal can be connected to the modula-
tion current regulation input (J6) via a
jumper wire as shown in Figure 1.
Data Sheet Rev.: 06
Figure 1. Jumper wire for automatic
Alternatively, the regulation of the modu-
lation current can be disabled and a
potentiometer P4 connected for simple,
manual setting of the modulation current.
This is done by connecting the jumper
wire as shown in Figure 2.
Figure 2. Jumper wire for manual
External circuits for regulation of pre-bias
and modulation current can be con-
nected via the center pins of jumper J7
and J6, respectively.
Figure 3. Location of jumpers J6 and J7
regulation
regulation
1
1
1
1
GD90573A
2
2
2
2
3
3
3
3
J6
J7
J6
J7
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