10Gbps Modulator Driver

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 (groundreferenced) 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 3.0VP-P 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 x 4mm, 24-pin thin QFN package and operates over the -40°C to +85°C temperature range.

Applications

* 10Gbps Ethernet * DWDM Systems * Long/Short-Reach Optical Transmitters * Mach Zehnder Modulators * Packaged Direct-Modulated Lasers * SONET OC-192 and SDH STM-64 Transmission Systems

* 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