622Mbps, Low-Noise Transimpedance Preamplifier for LAN and WAN Optical Receivers

The MAX3760 is a transimpedance preamplifier for 622Mbps ATM applications. It operates from a single +5V supply and typically consumes only 100mW power. The preamplifier converts a small photodiode current to a differential voltage. A DC cancellation circuit provides a true differential output swing over a wide range of input current levels, thus reducing pulsewidth distortion.

6.5kΩ transimpedance gain and 560MHz bandwidth, combined with low 73nA input-referred noise, provide -31.5dBm typical sensitivity in 1300nm receivers. The circuit accepts a 1mAP-P input current, resulting in a typical optical overload of -3dBm. The device operates over an extended temperature range of -40°C to +85°C.

The MAX3760 is internally compensated and requires few external components. In die form it includes a space-saving filter connection, which provides positive bias for the photodiode through a 1kΩ resistor to VCC. These features, combined with the die aspect ratio and dimensioning, allow the MAX3760 to assemble easily into a TO-style header with a photodiode.

The MAX3760 is designed to be used with either the MAX3761 or the MAX3762 limiting-amplifier ICs. When combined with a photodiode, the chipset forms a complete 5V, 622Mbps receiver. The MAX3760 is available in die form and in an 8-pin SO package.

Applications

* 622Mbps ATM LAN Optical Receivers * 622Mbps WAN Optical Receivers

* 73nA RMS Input-Referred Noise

* 560MHz Bandwidth

* 1mA Peak Input Current

* 6.5kΩ Gain

* Operation from -40°C to +85°C

* 100mW Typical Power Consumption

* Single +5V Supply