Rainbow Electronics MAX3941 - Manual

General Description
The MAX3941 is designed to drive an electro-absorp-
tion modulator (EAM) at data rates up to 10.7Gbps. It
incorporates the functions of a biasing circuit and a
modulation circuit, with integrated control op amps
externally programmed by DC voltages.
The integrated bias circuit provides a programmable
biasing current up to 50mA. This bias current reflects a
bias voltage of up to 1.25V on an external 50
Ω load. The
bias and modulation circuits are internally connected on
chip, eliminating the need for an external bias inductor.
A high-bandwidth, fully differential signal path is internally
implemented to minimize jitter accumulation. When a
clock signal is available, the integrated data-retiming
function can be selected to reject input-signal jitter.
The MAX3941 receives differential CML signals (ground
referenced) with on-chip line terminations of 50
Ω. The
output has a 50 Ω resistor for back termination and is
able to deliver a modulation current of 40mA P-P to
120mA
P-P
, with an edge speed of 23ps (20% to 80%
typ). This modulation current reflects an EAM modula-
tion voltage of 1.0V
P-P to 3.0V P-P .
The MAX3941 also includes an adjustable pulse-width
control circuit to precompensate for asymmetrical EAM
characteristics. It is available in a compact 4mm x
4mm, 24-pin thin QFN package and operates over the
-40°C to +85°C temperature range.
Features
♦ On-Chip Bias Network
♦ 23ps Edge Speed
♦ Programmable Modulation Voltage Up to 3V
P-P
♦ Programmable EAM Biasing Voltage Up to 1.25V
♦ Selectable Data-Retiming Latch
♦ Up to 10.7Gbps Operation
♦ Integrated Modulation and Biasing Functions
♦ 50Ω On-Chip Input and Output Terminations
♦ Pulse-Width Adjustment
♦ Enable and Polarity Controls
♦ ESD Protection
Applications
SONET OC-192 and SDH STM-64
Transmission Systems
DWDM Systems
Long/Short-Reach Optical Transmitters
10Gbps Ethernet
MAX3941
10Gbps EAM Driver with Integrated
Bias Network
________________________________________________________________ Maxim Integrated Products 1
MAX3952
0.01 µF
DATA+ DATA+
PLRT GND
EAM
50 Ω
0.01 µF
DATA- DATA- 50 Ω
0.01 µF
CLK+ CLK+
OUT
50 Ω
0.01 µF
CLK- CLK-
REPRESENTS A CONTROLLED-
IMPEDANCE TRANSMISSION LINE.
-5.2V
50 Ω
10Gbps
SERIALIZER
2k Ω
PWC+ PWC- V EE MODSET BIASSET
+
V
MODSET
-
+
V
BIASSET
- 330pF
-5.2V
-5.2V
0.1 µF
-5.2V
MODEN RTEN
50 Ω
MAX3941
Typical Application Circuit
19-2935; Rev 0; 7/03
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.
Ordering Information
PART TEMP RANGE PIN-PACKAGE
MAX3941ETG -40°C to +85°C
24-Thin QFN
(4mm x 4mm)