Microchip Technology

The SY88343BL low-power limiting post amplifier is designed for use in fiber-optic receivers. The device connects to typical transimpedance amplifiers (TIAs) that are AC-coupled. Th e linear signal output from TIAs can contain significant amounts of noise and may vary in amplitude over time. The SY88343BL quantizes these signals and outputs CML-level waveforms. The SY88343BL operates from a single +3.3V power supply, over temperatures ranging from -40°C to +85°C. With its wide bandwidth and high gain, signals with data rates up to 3.2Gbps and as small as 5mVPP can be amplified to drive devices with CML inputs or AC-coupled CML/PECL inputs. The SY88343BL generates a high-gain loss-of-signal (LOS) open-collector TTL output. The LOS function has a high gain input stage for increased sensitivity. A programmable loss-of-signal level set pin (LOS LVL) sets the sensitivity of the input amplitude detection. LOS asserts high if the input amplitude falls below the threshold set by LOS LVL and de-asserts low otherwise. The enable bar input (/EN) de-asserts the true output signal without removing the input signal. The LOS output can be fed back to the /EN input to maintain output stability under a loss-of-signal condition. Typically, 3.5dB LOS hysteresis is provided to prevent chattering.

The SY88349NDL is a high-sensitivity, burst-mode capable limiting post amplifier designed for optical line terminal (OLT) receiver applications. The SY88349NDL satisfies the strict timing restrictions of the GPON standards by providing ultra-fast loss-of-signal (LOS) or Signal-Detect (SD) output. Auto reset and manual reset options are provided to control LOS/SD output timing. For increased flexibility, this device also includes an option to select between LOS or SD output. The device can be connected to burst-mode capable transimpedance amplifiers (TIAs) using AC or DC coupling. The SY88349NDL generates a high-gain LOS or SD LVTTL output. A programmable LOS/SD level set pin (LOS/SDLVL) sets the sensitivity of the input amplitude detection. When LOS/SD SEL pin is left open or tied to VCC, JAM is active high, SD is selected and asserts high if the input amplitude rises above the threshold sets by LOS/SDLVL and de-asserts low otherwise. When LOS/SD SEL pin is set low or tied to GND, JAM is active low, LOS is selected and asserts low if the input amplitude rises above the threshold sets by LOS/SDLVL and de-asserts high otherwise. The LOS/SD output can be fed back to the JAM input to maintain output stability under an invalid signal conditions. Typically, 4dB  5dB SD hysteresis is provided to prevent chattering. The SY88349NDL also features a selectable proprietary noise discriminator that aids by filtering out input signals that do not qualify as a 2.5Gbps GPON preamble signal in the initial startup phase. This feature minimizes false SD asserts that can be triggered by random noise. The SY88349NDL operates from a single +3.3V power supply, over temperatures ranging from –40°C to +85°C. With its wide bandwidth and high gain, signals up to 2.5Gbps and as small as 5mVpp can be amplified to drive devices with CML inputs.

The SY88353BL limiting post amplifier is designed for use in fiber-optic receivers, and is specially optimized for WDM applications where optical amplifiers such as EDFAs and Raman amplifier are used. The device connects to typical transimpedance amplifiers (TIAs). The linear signal from TIAs can contain significant amounts of noise that is unevenly distributed between top and bottom rails due to the ASE noise generated by the optical amplifiers, crosstalk, or non-linear effect in the fiber. In order to optimize the BER in such noisy conditions, the decision threshold between bit 1 and bit 0, needs to be moved to the rail that contains less noise. The SY88353BL features a pin at which an external voltage can be applied to move the crossing point up and down, from 20% to 80%, for BER optimization purposes. The SY88353BL operates from a single +3.3V power supply, over temperatures ranging from -40°C to +85°C. Signals with data rates from 155Mbps up to 3.2Gbps, and as small as10mVPP, can be amplified to drive devices with CML or PECL inputs. The SY88353L features a Loss-of-Signal (LOS) open-collector TTL output. A programmable Loss-of-Signal level set pin (LOS LVL) sets the sensitivity of the input amplitude detection. LOS asserts high if the input amplitude falls below the threshold sets by LOS LVL and de-asserts low otherwise. The enable bar input (/EN) de-asserts the true output signal without removing the input signal. The LOS output can be fed back to the /EN input to maintain output stability under a loss-of-signal condition. Typically, 3.3dB LOS hysteresis is provided to prevent chattering.

The SY88403BL is a low-power limiting post amplifier optimized for copper applications. 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 SY88403BL quantizes these signals and outputs typically 800mVPP voltage-limited waveforms. The SY88403BL operates from a single +3.3V ±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 4.25Gbps and as small as 20mVPP can be amplified to drive devices with CML inputs or AC-coupled PECL inputs. The SY88403BL 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 bar (/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 3.5dB LOS hysteresis is provided to prevent chattering.

The SY88422L is a single 3.3V supply, small form factor laser driver for telecom/datacom applications up to 4.25Gbps. The driver can deliver modulation current up to 90mA and a bias current up to 100mA.