MAXIM MAX3277EVKIT

19-2264; Rev 0; 12/01
MAX3277 Evaluation Kit
Features
♦ Fully Assembled and Tested
♦ Includes Photodiode Emulation Circuit
♦ Includes Calibration Circuit for Accurate
Bandwidth and Jitter Measurements
Component List
DESIGNATION
QTY
Ordering Information
DESCRIPTION
PART
TEMP RANGE
IC PACKAGE
MAX3277EVKIT
0°C to +85°C
MAX3277UID
Chip On-Board
C1
1
0.01µF ±10% ceramic capacitor
(0402)
C2
1
10µF ±10% tantalum capacitor
C5–C9
5
0.1µF ±10% ceramic capacitors
(0402)
C11, C12
2
1000pF ±10% ceramic capacitors
(0402)
FAX
5
SMA connectors, edge mount
(round contact)
PHONE
J1–J5
AVX
843-444-2863
843-626-3123
J8
1
1 × 2-pin header (0.1in center)
Coilcraft
408-224-8566
408-224-6304
Murata
415-964-6321
415-964-8165
Ventel
800-950-8365
512-794-0087
L1
1
56nH inductor
Coilcraft 0805CS-560XKBC
R1, R6
2
49.9Ω ±1% resistors (0402)
R2, R5
2
1kΩ ±1% resistors (0402)
R3, R4, R7, R8
4
499Ω ±1% resistors (0402)
TP1, TP2, J6, J7
4
Test points
MAX3277U/D die
U1
1
None
1
MAX3277 EV kit circuit board
None
1
MAX3275/MAX3277 data sheet
Component Suppliers
SUPPLIER
Note: Please indicate that you are using the MAX3277 when
contacting these component suppliers.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
Evaluates: MAX3277
General Description
The MAX3277 evaluation kit (EV kit) allows complete
evaluation of the MAX3277 transimpedance amplifier.
The EV kit includes a circuit that emulates the highspeed, zero-to-peak current input signal that would be
produced by a photodiode. The kit also includes a calibration circuit that allows accurate bandwidth and jitter
measurements.
The MAX3277 EV kit is fully assembled and tested.
Evaluates: MAX3277
MAX3277 Evaluation Kit
Quick Start
1) Connect a signal source to IN (J3). Set the signal
amplitude to 50mVP-P (corresponding to 50µAP-P
current into the TIA). This may require attenuation
between the source and the MAX3277 EV kit. The
signal should have a data rate of up to 2.125Gbps.
2) Apply 30µA to TP1 using a constant current source
to emulate the DC component of the input signal.
3) Connect OUT+ (J1) and OUT- (J2) to the 50Ω
inputs of a high-speed oscilloscope.
4) Remove the shunt from jumper J8 to enable DC
cancellation loop.
5) Connect a 3.3V supply to the VCC terminal (J6) and
ground to the GND terminal (J7).
6) The differential signal at the oscilloscope should be
approximately 165mVP-P.
Detailed Description
The MAX3277 EV kit allows characterization of the
MAX3277 TIA without a photodiode. The MAX3277 is
designed to accept a DC-coupled input from a highspeed photodiode. Diode currents can have 10µAP-P to
2mAP-P AC current with a DC component from 5µA to
1mA. The high-speed current source of the photodiode
is emulated on the EV kit using separate AC and DC
paths. The AC signal is supplied from a standard 50Ω
lab source that delivers power to an on-board termination resistor. A current is then generated from the voltage signal by a resistor with low stray capacitance. The
effect of the DC photodiode current can be emulated
by a current source at TP1. An isolation resistor prevents the DC source from loading the AC path.
The values of the series-resistive elements, R4 and R7,
have been selected carefully so that the bandwidth of
the transimpedance amplifier is not altered. Surface-
2
mount resistors have parasitic capacitance that reduces
their impedance at frequencies above 1GHz. Changes
to R4 and R7 must be evaluated using the calibration
network.
Photodiode Emulation
Use the following procedure to emulate the high-speed
current signal generated by a photodiode:
1) Select the desired optical power (PAVE in dBm) and
extinction ratio (re).
2) Calculate the average current (IAVE in Amps). Set the
DC current at TP1 to IAVE:
 10(PAVE / 10) 
IAVE = 
 ρ
1000


(ρ = photodiode responsivity in A / W)
3) Calculate the AC signal current (lAC) and adjust the
signal generator to obtain it:
 r − 1
IAC = 2IAVE  e 
 re + 1
For example: To emulate a photodiode with an average power of -16dBm and an extinction ratio of 10:
1) -16dBm optical power will produce 25µA of average
input current (assume photodiode responsivity of
1A/W). Set the DC current input to 25µA at TP1.
2) The AC signal current is 2 IAVE (re - 1)/(re + 1) = 41µA.
To generate this current through the 1000Ω input
resistors, set the signal source to produce an output
level of 41µA (1000Ω) = 41mVP-P.
_______________________________________________________________________________________
MAX3277 Evaluation Kit
J6
VCC
L1
56nH
J7
GND
C7
0.1µF
VCC
C12
1000pF
J4
CALIN
C2
10µF
R2
1kΩ R8
499Ω
R1
49.9Ω
C1
0.01µF
VCC
1
TP1
2
J3
IN
C11
1000pF
5
R5
1kΩ R7
499Ω
J5
CALOUT
VCC
C9
0.1µF
C8
0.1µF
R3
499Ω
R4
499Ω
8
VCC
VCCZ
GND
U1
FILTER
GNDZ
MAX3277
OUT+
IN
OUT-
9
7
J8
J1
OUT+
4
3
C5
0.1µF
J2
OUTC6
0.1µF
R6
49.9Ω
PC BOARD FEATURES
EMULATING
CAPACITORS
Figure 1. MAX3277 EV Kit Schematic
_______________________________________________________________________________________
3
Evaluates: MAX3277
TP2
Evaluates: MAX3277
MAX3277 Evaluation Kit
Figure 2. MAX3277 EV Kit Component Placement Guide—
Component Side
4
_______________________________________________________________________________________
MAX3277 Evaluation Kit
Evaluates: MAX3277
Figure 3. MAX3277 EV Kit PC Board Layout—Component Side
_______________________________________________________________________________________
5
Evaluates: MAX3277
MAX3277 Evaluation Kit
Figure 4. MAX3277 EV Kit PC Board Layout—Solder Side
6
_______________________________________________________________________________________
MAX3277 Evaluation Kit
Evaluates: MAX3277
Figure 5. MAX3277 EV Kit PC Board Layout—Ground Plane
_______________________________________________________________________________________
7
Evaluates: MAX3277
MAX3277 Evaluation Kit
Figure 6. MAX3277 EV Kit PC Board Layout—Power Plane
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.