Microchip Technology

The SY88773V low-power, limiting post amplifier is designed for use in fiber optic receivers. The device connects 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 SY88773V quantizes these signals and outputs typically 800mVPP voltage-limited waveforms. The SY88773V operates from a single +3.3V±10% or +5V±10% power supply, over an industrial temperature range of -40°C to +85°C. With its wide bandwidth and high gain, signals with data rates up to 3.2Gbps and as small as 10mVPP can be amplified to drive devices with CML inputs or AC-coupled PECL inputs. The SY88773V incorporates a loss-of-signal (LOS), open-collector TTL output with internal 4.75kΩ pull-up resistor. A programmable, loss-of-signal level set pin (LOSLVL) sets the sensitivity of the input amplitude detection. LOS asserts high if the input amplitude falls below the threshold set by LOSLVL and de-asserts low otherwise. LOS can be fed back to the enable (/EN) input to maintain output stability under a loss-of-signal condition. /EN de-asserts the true output signal without removing the input signal. Typically 4.6dB LOS hysteresis is provided to prevent chattering. Please see Micrel's website at www.micrel.com for a complete selection of optical module ICs. The following table summarizes the differences between devices in Micrel's latest family of Limiting Amplifiers.

The SY88803V low power limiting post amplifier is designed for use in fiber-optic receivers. The device connects 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 SY88803V quantizes these signals and outputs PECL level waveforms. The SY88803V operates from a single +3.3V or +5V power supply, over temperatures ranging from -40°C to +85°C. With its wide bandwidth and high gain, signals with data rates up to 155Mbps and as small as 5mVp-p can be amplified to drive devices with PECL inputs. The SY88803V generates a TTL LOS output. A programmable loss-of-signal level set pin (LOSLVL) sets the sensitivity of the input amplitude detection. LOS asserts high if the input amplitude falls below the threshold set by LOSLVL and deasserts low otherwise. /EN deasserts the true output signal without removing the input signal. Typically 4.6dB loss-of-signal hysteresis is provided to prevent chattering.