Date: 27/05/2010

Low-jitter transmit/receive chipset enable low power SFP+ module operation

Maxim has introduced a 1.0625Gbps to 11.3Gbps transmit/receive solution composed of the MAX3946 laser driver with impedance-mismatch tolerance and the MAX3945 dual-path limiting amplifier. This 10GBASE-SR/LR SFP+ transmit/receive chipset consists of MAX3946, MAX3945 consume 355mW to fulfill the power budget needs of the 1W SPF+ optical module. Both ICs include a 3-wire digital control interface with integrated control DACs. Maxim says these devices' outstanding jitter performance eases design tolerances and improves manufacturing yield in SFP+ optical transceivers. This chipset is suggested for Ethernet and fibre channel transmission systems at data rates up to 11.3Gbps.

The MAX3946 can drive a differential transmitter optical subassembly (TOSA) with a 25ohm flex circuit up to 100mA modulation current and up to 80mA bias current. This design of the output stage enables the use of unmatched TOSAs to reduce headroom limitations and lower module power consumption by 100mW, with 5ps P-P deterministic jitter.

The MAX3945 is a 3.3V, multirate, high-sensitivity limiting amplifier that limits the signal generated by a transimpedance amplifier into a CML-level differential output signal. The dual-path limiting amplifier's programmable filter optimizes sensitivity for different data rates and suppresses relaxation oscillations that could occur in legacy optical systems.

Package:
The MAX3946 comes in a 4mm x 4mm, 24-pin TQFN.
The MAX3945 comes in a 3mm x 3mm, 16-pin TQFN.

Operating temperature range: -40degC to +95degC.

Price: starts at US$3.60

For more information visit: www.maxim-ic.com.