General Description

The MAX3942 is designed to drive high-speed optical modulators at data rates up to 10.7Gbps. It functions as a modulation circuit, with an integrated control op amp externally programmed by a DC voltage.

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 MAX3942 receives differential CML signals (ground referenced) with on-chip line terminations of 50Ω. Each of the differential outputs has an on-chip 50Ω resistor for back termination. The driver is able to deliver a modulation current of 40mAP-P to 120mAP-P, with an edge speed of 23ps (typical 20 to 80). This modulation current reflects a modulation voltage of 1.0VP-P to 3.0VPP single ended or 2.0VP-P to 6.0VP-P differential.

The MAX3942 also includes an adjustable pulse-width control circuit to precompensate for asymmetrical modulator characteristics. It is available in a compact 4mm ✕ 4mm, 24-pin thin QFN package and operates over the -40°C to +85°C temperature range.

Features

♦ 23ps Edge Speed

♦ Single-Ended Modulation Voltage Up to 3VP-P

♦ Differential Modulation Voltage Up to 6VP-P

♦ Selectable Data-Retiming Latch

♦ Up to 10.7Gbps Operation

♦ 50Ω On-Chip Input and Output Terminations

♦ Pulse-Width Adjustment

♦ Enable and Polarity Controls

♦ ESD Protection

Applications

   Mach Zehnder Modulators

   Packaged Direct-Modulated Lasers

   SONET OC-192 and SDH STM-64 Transmission Systems

   DWDM Systems

   Long/Short-Reach Optical Transmitters

   10Gbps Ethernet