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.
Multi-rate up to 3.2Gbps operation
Wide gain-bandwidth product
38dB differential gain
2GHz 3dB bandwidth
Low noise 50 CML data outputs
800mVPP output swing
60ps edge rates
5psrms typ. random jitter
15psPP typ. deterministic jitter
Chatter-free, Loss-of-Signal (LOS) output
4.6dB electrical hysteresis
OC-TTL output with internal 4.75kΩ pull-up resistor
Programmable LOS sensitivity using single external resistor
Integrated input bias reference
TTL /EN input allows feedback from LOS
Wide operating range
Single 3.3V±10% or 5±10% power supply
-40°C to +85°C industrial temperature range
Available in tiny 10-pin EPAD-MSOP and 16-pin MLF®packages