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.
Additional Features
<5ns SD assert (LOS deassert) time
Proprietary noise discriminator feature
Option to AUTO RESET or manual RESET LOS/SD output
Selectable LOS/SD option
Up to 2.5Gbps operation
Low-noise CML data outputs
5mVPP input sensitivity
High-sensitivity LOS/SD signal detect
LVTTL LOS/SD output with an external pull-up resistor
Squelching function to maintain output stability
Programmable LOS/SD level set (LOS/SDLVL)
Single 3.3V power supply
Available in a 16-pin (3mm x 3mm) QFN package
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.
Additional Features
- <5ns SD assert (LOS deassert) time
- Proprietary noise discriminator feature
- Option to AUTO RESET or manual RESET LOS/SD output
- Selectable LOS/SD option
- Up to 2.5Gbps operation
- Low-noise CML data outputs
- 5mVPP input sensitivity
- High-sensitivity LOS/SD signal detect
- LVTTL LOS/SD output with an external pull-up resistor
- Squelching function to maintain output stability
- Programmable LOS/SD level set (LOS/SDLVL)
- Single 3.3V power supply
- Available in a 16-pin (3mm x 3mm) QFN package
