Postamplifiers are intended for applications where the receiver optical subassemblies with low-cost/low-gain transimpedance amplifiers and/or PIN photodiodes are used

New from Micrel, the SY88343HL and SY88289HL are high-sensitivity low-power CML limiting postamplifiers, designed with twice the signal gain of Micrel’s existing devices. These solutions are targeted at applications using low-cost transimpedance amplifiers and/or low gain PIN diodes which occur in a wide variety of data and telecomms markets including PON, Gigabit Ethernet, SFP/SFF optical transceivers, 1x and 2x Fibre Channel, and Sonet/SDH: OC3/12/24/48 - STM 1/4/8/16 datarates.

Both devices are currently in volume production with pricing for 1000-unit quantities starting at US $2.49.

‘Higher gain, high-sensitivity post amplifiers exhibit better bit error rate (BER) performance as a result of bigger eye opening when detecting and receiving very weak signals’, says Thomas S Wong, Vice President High Bandwidth Products for Micrel.

‘These devices are recommended for systems that have stringent BER and low cost requirements’.

In a fibre optic module, the devices connect to typical transimpedance amplifiers (TIAs).

The linear signal output from TIAs can contain significant amounts of noise and may vary in amplitude over time.

The SY88289HL and SY88343HL quantise these signals and output them in low noise CML-level waveforms.

The SY88343HL and SY88289HL both feature high input sensitivity and can amplify input signals as small as 4mV peak-peak to drive CML/PECL devices.

The SY88343HL has the same footprint as all other Micrel postamplifiers, which allow for flexible upgrades and interchangeability.

These solutions also feature high-sensitivity loss-of-signal circuits which are ideal for detecting very small input signals.

The new postamplifiers are intended for applications where the receiver optical subassemblies (ROSAs) with low-cost/low-gain transimpedance amplifiers and/or PIN photodiodes are used.

The devices have wide bandwidth, high gain, and are optimised to operate over a wide range of datarates, from 155Mbit/s to 3.2Gbit/s.

Both Post Amplifiers have chatter-free open collector TTL LOS outputs with adjustable LOSlvl threshold.

The ICs can amplify as low as 4mv signals to drive devices with CML and PECL inputs.

Each device operates from a single 3.3V power supply, over temperatures ranging from -40 to +85C and comes in a tiny 3 x 3mm 16-pin MLF package.