Evaluates: MAX3669 MAX3669 Evaluation Kit General Description Features

19-1594 Rev 1; 2/01
MAX3669 Evaluation Kit
The MAX3669 evaluation kit (EV kit) is an assembled
demonstration board that provides easy optical or electrical evaluation of the MAX3669, a 622Mbps laser driver with current monitors and automatic power control
(APC) circuitry. Although the MAX3669 EV kit is
shipped in the electrical configuration, this EV kit also
provides configuration instructions for optical operation.
Features
♦ Fully Assembled and Tested
♦ +3.3V or +5V Operation
♦ On-Board Input Termination
♦ Independent Electrical Monitoring of Modulation
and Bias Currents
Component Suppliers
PHONE
FAX
AVX
SUPPLIER
803-946-0690
803-626-3123
Coilcraft
847-639-6400
847-639-1469
PART
TEMP. RANGE
IC PACKAGE
Murata
814-237-1431
814-238-0490
MAX3669EVKIT
-40°C to +85°C
32 TQFP
Zetex
516-543-7100
516-864-7630
Ordering Information
Note: Please indicate that you are using the MAX3669 when
contacting these component suppliers.
Component List for Electrical Configuration
DESIGNATION
QTY
DESCRIPTION
DESIGNATION
QTY
DESCRIPTION
C1, C12
2
0.01µF ±10% ceramic caps (0402)
R18
1
110Ω ±5% resistor (0603)
C2, C3, C6, C20
4
0.01µF ±10% ceramic caps (0603)
R20
1
0Ω resistor (0402)
C4, C7, C10, C11
4
1µF ceramic capacitors (0805)
R23
1
15Ω ±5% resistor (0603)
C8
1
100pF ±10% ceramic cap (0402)
R26, R28
2
392Ω ±1% resistors (0603)
C16
1
0.1µF ±10% ceramic capacitor (0805)
U1
1
MAX3669EHJ 32-pin TQFP
1
10µF ±10%, 10V min tantalum cap
AVX TAJC106K016
U3
1
MAX495ESA 8-pin SOIC
VCC, GND, TP1,
TP4, TP5, TP6,
TP8–TP11
10
Test points
C19
C21
1
5pF ±5% ceramic capacitor (0402)
D1
1
LED
J1, J2, J5
3
SMA connectors (edge mount)
None
1
MAX3669 data sheet
L3
1
1.2µH inductor
Coilcraft 1008LS-122XKBC
None
1
MAX3669 EV kit PC board
(Rev. A)
P1
1
2-pin header (0.1in centers)
None
1
Shunt for P1
Q1
1
R1, R2, R24
3
PNP transistor
Zetex FMMT591A
1.5kΩ ±5% resistors (0603)
R3
1
1.0kΩ ±5% resistor (0603)
R5
1
12.4Ω ±1% resistor (0402)
R6, R7, R21
3
84.5Ω ±1% resistors (0603)
R8, R9
2
124Ω ±1% resistors (0603)
R10, R11
2
20Ω ±1% resistors (0603)
R12
1
10Ω ±1% resistor (0402)
R13, R22, R25
3
0Ω resistors (0603)
R14
1
50kΩ variable resistor
R15
R16
1
1
200kΩ variable resistor
100kΩ variable resistor
Component Modifications
for Optical Configuration
DESIGNATION QTY
DESCRIPTION
J5
1
Remove
L2
1
3.3µH inductor
Coilcraft 1008CS-332XKBC
R5
1
Remove
R13
1
Remove
R19
1
20Ω ±5% resistor (0402)
R20
1
5Ω ±5% resistor (0402)
R22
1
Remove
R23
1
Remove
U2
1
User-supplied laser diode
________________________________________________________________ Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
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Evaluates: MAX3669
General Description
Evaluates: MAX3669
MAX3669 Evaluation Kit
Quick Start
Electrical Setup (Default)
In the electrical configuration, an APC test circuit is
included to emulate a semiconductor laser with a monitor photodiode. Monitor diode current is provided by
Q1, which is controlled by an operational amplifier (U3).
The APC test circuit, consisting of U3 and Q1, applies
the simulated monitor diode current to the MAX3669’s
MD pin. The ratio of IBIAS / IMD is R24 / R23 = 100. To
ensure proper operation in the electrical configuration,
set up the evaluation board as follows:
1) Verify inductor L2 is not installed.
2) Remove the shunt from P1 to enable the output.
Note: When performing the following resistance
checks, manually set the ohmmeter to a high range to
avoid forward biasing the on-chip ESD protection
diodes.
3) Adjust R14, the MOD (RMODSET) potentiometer, for
10kΩ resistance between pins 2 and 3 (test point 5
and ground).
4) Adjust R15, the BIAS (RBIASMAX) potentiometer, for
10kΩ resistance between pins 2 and 3 (test point 4
and ground).
5) Adjust R16, the APC (RAPCSET) potentiometer, for
10kΩ resistance between pins 2 and 3 (test point 6
and ground).
6) Power up the board with a +3.3V supply.
7) Apply a differential input signal (max amplitude
≤800mV per side) to J1 and J2 (DATA+ and DATA-).
8) Attach a high-speed oscilloscope with 50Ω inputs
to J5.
9) Adjust RBIASMAX (R15) and RAPCSET (R16) until the
desired laser-bias current is achieved (refer to the
note in the Applications Information section of the
MAX3669 data sheet).
10) Adjust RMODSET (R14) until the desired laser-modulation current is achieved.
Note: See Adjustment and Control Descriptions.
2
Optical Setup
For optical operation, the electrical APC test circuit
must be disabled. For optical evaluation of the MAX3669,
configure the EV kit as described in Component
Modifications for Optical Configuration:
1) Remove the shunt from P1 to enable the output.
2) Connect a TO-style header laser and monitor diode
(Figure 1) as follows:
• Keeping the leads to the laser diode as short as
possible, connect the laser diode on the component side of the board between R20 and V CC
with the cathode connected to R20 and the
anode connected to VCC.
• Connect the monitor diode on the underside of the
the board with the anode connected to the
MAX3669’s MD pin and the cathode connected to
VCC.
Note: When performing resistance checks, manually
set the ohmmeter to a high range to avoid forward biasing the on-chip ESD protection diodes.
3) Adjust R14, the MOD (RMODSET) potentiometer, for
maximum resistance between pins 2 and 3 (test
point 5 and ground).
4) Adjust R15, the BIAS (RBIASMAX) potentiometer, for
maximum resistance between pins 2 and 3 (test
point 4 and ground).
5) Adjust R16, the APC (RAPCSET) potentiometer, for
desired optical power. (Refer to the Design
Procedure section of the MAX3669 data sheet.)
6) Power up the board with a +3.3V supply.
7) Apply a differential input signal (≤800mV per side)
to J1 and J2 (DATA+ and DATA-).
8) Attach the laser-diode output to an optical/electrical
converter.
9) Adjust R15 until LED D1 is no longer illuminated.
Laser power can be monitored at the laser diode
with an optical/electrical converter (refer to the note
in the Applications Information section of the
MAX3669 data sheet).
10) Adjust R14 until the desired optical amplitude is
achieved. Optical amplitude can be observed on an
oscilloscope connected to an optical/electrical converter.
_______________________________________________________________________________________
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MAX3669 Evaluation Kit
Evaluates: MAX3669
CONFIGURATION 1
CONFIGURATION 2
TOP OF PC BOARD
TOP OF PC BOARD
L2
VCC
VCC
L2
VCC
VCC
D3
D3
TO-46 CAN
LASER/PHOTODIODE
PAIR
LD
TO-46 CAN
LASER/PHOTODIODE
PAIR
LD
BOTTOM OF PC BOARD
PD
BOTTOM OF PC BOARD
PD
SOLDER
BRIDGES
VCC
VCC
VCC
SOLDER
BRIDGES
CONFIGURATION 3
CONFIGURATION 4
TOP OF PC BOARD
VCC
VCC
D3
D3
TO-46 CAN
LASER/PHOTODIODE
PAIR
LD
BOTTOM OF PC BOARD
SOLDER
BRIDGES
TOP OF PC BOARD
L2
L2
VCC
VCC
VCC
PD
VCC
VCC
LD
TO-46 CAN
LASER/PHOTODIODE
PAIR
BOTTOM OF PC BOARD
SOLDER
BRIDGES
PD
VCC
VCC
Figure 1. Attachment of Laser Diode/Monitor Diode to MAX3669 EV Kit
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3
GND
VCC
DATA-
DATA+
J2
J1
P5
P4
R24
1.5k
L3
1.2µH
R21
84.5Ω
R9
124Ω
R8
124Ω
R6
84.5Ω
Figure 2. MAX3669 EV Kit Schematic—Electrical Configuration
_______________________________________________________________________________________
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MD
R13
0Ω
Q1
FMMT591A
VCC
C11
1µF
C10
1µF
C19
10µF
VCC
R7
84.5Ω
5
VCC
MAX495
C12
0.01µF
R27
CW
7
U3
4
VCC
VCC
R23
15Ω
VCC
C6
0.01µF
BIAS
3
2
VCC
C20
0.01µF
R29
R26
392Ω
TP8
C3
0.01µF
C2
0.01µF
CW
R15
200k RBIASMAX
R25
0Ω
P3
9
MODMON
BIASMON
VCC
GND
DATA-
VCC
R22
0Ω
TP9
10
11
29 28
R3
1.0k
R2
1.5k
31 30
DATA+
VCC
VCC
TP10
P1
TP11
8
7
6
5
4
3
2
1
32
R1
1.5k
TP4
TP5
GND
FAIL
R14
50k RMODSET
R28
392Ω
VCC
CW
U1
27
R4
R18
110Ω
14
C5
TP1
C18
D1
RED
12
13
MAX3669
N.C.
BIASMAX
ENABLE
APCSET
TP6
26
TP7
15
N.C.
GND
R16
100k RAPCSET
MODSET
GND
N.C.
N.C.
25
16
VCC
OUT+
OUT-
VCC
GND
GND
MD
VCC
CAPC
VCC
R17
N.C.
VCC
VCC
4
BIAS
17
18
19
20
21
22
23
24
VCC
BIAS
C16
0.1µF
C15
VCC
VCC
VCC
VCC
C8
100pF
C1
0.01µF
C9
L2
R10
20Ω
TP3
R11
20Ω
C7
1µF
C4
1µF
R20
0Ω
R12
10Ω
C21
5pF
R19
MD
R5
12.4Ω
J5
OUT
Evaluates: MAX3669
MAX3669 Evaluation Kit
www.BDTIC.com/maxim
VCC
GND
DATA-
DATA+
J2
J1
VCC
P5
P4
R24
1.5k
L3
1.2µH
R21
84.5Ω
R9
124Ω
R8
124Ω
MD
R13
VCC
R7
84.5Ω
C19
10µF
R6
84.5Ω
Q1
FMMT591A
VCC
C11
1µF
C10
1µF
VCC
MAX495
C12
0.01µF
R27
R28
392Ω
VCC
5
7
U3
4
VCC
VCC
R23
VCC
C6
0.01µF
BIAS
3
2
VCC
C20
0.01µF
R29
R26
392Ω
TP8
C3
0.01µF
C2
0.01µF
CW
200k R
BIASMAX
R22
DATA-
R25
0Ω
P3
9
MODMON
BIASMON
VCC
GND
VCC
TP9
R2
1.5k
10
11
31 30
DATA+
VCC
VCC
TP10
P1
TP11
8
7
6
5
4
3
2
1
32
R1
1.5k
TP4
29 28
R3
1.0k
GND
FAIL
TP5
U1
27
R4
R18
110Ω
14
C5
TP1
C18
D1
RED
12
13
MAX3669
N.C.
BIASMAX
ENABLE
APCSET
26
TP7
15
N.C.
GND
RMODSET
CW
R15
MODSET
GND
N.C.
N.C.
25
16
VCC
OUT+
OUT-
VCC
GND
GND
MD
VCC
CAPC
BIAS
TP6
N.C.
VCC
VCC
R16
100k RAPCSET
CW
R14
50k
17
18
19
20
21
22
23
24
VCC
BIAS
C16
0.1µF
C15
VCC
VCC
VCC
VCC
C8
100pF
C1
0.01µF
C9
L2
3.3µH
R10
20Ω
TP3
C7
1µF
C4
1µF
C21
5pF
R19
20Ω
R20
5Ω
R12
10Ω
R5
* TO PHOTOLASER (SEE FIGURE 1 FOR
PHOTOLASER CONNECTION).
R11
20Ω
*
MD
VCC
Evaluates: MAX3669
R17
MAX3669 Evaluation Kit
Figure 3. MAX3669 EV Kit Schematic—Optical Configuration
_______________________________________________________________________________________
5
Evaluates: MAX3669
MAX3669 Evaluation Kit
Figure 4a. MAX3669 EV Kit Component Placement Guide—Component Side
6
_______________________________________________________________________________________
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MAX3669 Evaluation Kit
See Quick Start first.
COMPONENT
NAME
FUNCTION
D1
APC Fail Indicator LED
Refer to the Design section of the MAX3669 data sheet. Set APC current;
then increase bias current until LED goes off (LED is illuminated when the
APC loop is open and off when the APC loop is closed).
J5
Electrical Output SMA
Electrical Output. Remove for optical operation.
P1
OUTPUT DISABLE
R14
RMODSET
Laser Modulation Current Adjustment
R15
RBIASMAX
Laser-Bias Current Adjustment. In open-loop mode, R15 adjusts the laserbias current. In closed-loop operation, R15 adjusts the maximum laser-bias
current.
R16
RAPCSET
Automatic Power Control Adjustment. For closed-loop operation, R16
adjusts the monitor-diode current level.
TP1
Fail Indicator Test Point
Enable/Disable the Output Currents. Shunting disables the part. Remove
shunt for normal operation.
TTL low level indicates a failure in the APC loop.
1.0"
1.0"
Figure 4b. MAX3669 EV Kit Component Placement Guide—
Component Side
Figure 5. MAX3669 EV Kit PC Board Layout—Component Side
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7
Evaluates: MAX3669
Adjustment and Control Descriptions
Evaluates: MAX3669
MAX3669 Evaluation Kit
1.0"
1.0"
Figure 6. MAX3669 EV Kit PC Board Layout—Solder Side
1.0"
Figure 7. MAX3669 EV Kit PC Board Layout—Ground Plane
1.0"
Figure 8. MAX3669 EV Kit PC Board Layout—Power Plane
Figure 9. MAX3669 EV Kit Component Placement Guide—
Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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