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Post amplifiers feature LOS or signal detect circuits

San Jose, Calif. — Micrel Inc. has added four devices to its family of post amplifiers. All four low-power devices — the SY88303BL, SY88305BL, SY88307BL and SY88309BL — feature loss-of-signal (LOS) or signal detect circuits, which are optimized to detect a wide input signal range. This feature is well-suited for copper module applications and fiber-optic module designs that use high gain receiver optical sub-assemblies (ROSAs).

These receiver designs typically use an avalanche photodiode (APD) or high gain transimpedance amplifier (TIA). The solutions are targeted at a variety of data and telecommunications markets including PON, Gigabit Ethernet, 1x and 2x Fiber Channel, and SONET/SDH: OC3/12/24/48 — STM 1/4/8/16 data rates.

The SY88303BL and SY88307BL both feature a LOS circuit that is optimized to detect a larger and wider input signal range. Both optimized LOS/SD circuits are designed for applications where avalanche photodiodes and/or high-gain transimpedance amplifiers are used where a significant amount of noise can be added to the signal. Also, these post amplifier solutions can be used in copper module and backplane applications where the signal levels are normally much higher.

The SY88303BL and SY88305BL have CML-level outputs whereas the SY88307BL and SY88309BL have higher swing PECL-level outputs. The devices are also well-suited for operation in multi-rate applications from 155 Mbits/s to 3.2 Gbits/s. The detectable input range extends from 20 mVpp to 140 mVpp, which is wider than the range offered by devices currently available on the market, said Micrel. The devices also feature adjustable LOS threshold, internal 50-ohm termination, and high gain through their data paths.

The SY88305BL and SY88309BL are identical to the SY88303BL and SY88307BL devices except they include a signal detect (SD) circuit instead of a LOS circuit. The different data output and input detection circuit options offer system designers greater flexibility.

These products are suited for multi-rate applications where the same post amplifier is optimized to operate over a wide range of data rates and signal amplitudes. They do not require external compensation and can operate from 155 Mbits/s to 3.2 Gbits/s with signal amplitudes ranging from 10 mVpp to 1800 mVpp. All these devices are offered in an ultra-small 16-pin MLF package. The ICs also come in a 10-pin EPAD-MSOP package option.

Pricing: Starts at $2.49 in quantities of 1,000
Availability: All devices are currently in volume production.
Product information: limiting post amplifiers (including datasheets)

Micrel, Inc. , www.micrel.com

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